Action not permitted
Modal body text goes here.
Modal Title
Modal Body
Vulnerability from cleanstart
Published
2026-07-30 07:10
Modified
2026-07-30 09:37
Summary
Security fixes in elasticsearch 9.2.8-r2
Details
Package elasticsearch version 9.2.8-r2 fixes 6 vulnerabilities: CVE-2025-68161, CVE-2026-34477, CVE-2026-34478, CVE-2026-34480, CVE-2026-34479...
References
| URL | Type | |
|---|---|---|
{
"affected": [
{
"package": {
"ecosystem": "Alpine",
"name": "elasticsearch"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "9.2.8-r2"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"9.2.8-r2"
]
}
],
"credits": [],
"database_specific": {},
"details": "Package elasticsearch version 9.2.8-r2 fixes 6 vulnerabilities: CVE-2025-68161, CVE-2026-34477, CVE-2026-34478, CVE-2026-34480, CVE-2026-34479...",
"id": "CLEANSTART-2026-SD03557",
"modified": "2026-07-30T09:37:48Z",
"published": "2026-07-30T07:10:53Z",
"references": [
{
"type": "WEB",
"url": "https://www.elastic.co/products/elasticsearch"
}
],
"related": [],
"schema_version": "1.7.3",
"summary": "Security fixes in elasticsearch 9.2.8-r2",
"upstream": [
"CVE-2025-68161",
"CVE-2026-34477",
"CVE-2026-34478",
"CVE-2026-34480",
"CVE-2026-34479",
"CVE-2026-59949"
]
}
CVE-2025-68161 (GCVE-0-2025-68161)
Vulnerability from cvelistv5 – Published: 2025-12-18 20:47 – Updated: 2026-04-10 16:18
VLAI
EPSS
VEX
Title
Apache Log4j Core: Missing TLS hostname verification in Socket appender
Summary
The Socket Appender in Apache Log4j Core versions 2.0-beta9 through 2.25.2 does not perform TLS hostname verification of the peer certificate, even when the verifyHostName https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName configuration attribute or the log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName system property is set to true.
This issue may allow a man-in-the-middle attacker to intercept or redirect log traffic under the following conditions:
* The attacker is able to intercept or redirect network traffic between the client and the log receiver.
* The attacker can present a server certificate issued by a certification authority trusted by the Socket Appender’s configured trust store (or by the default Java trust store if no custom trust store is configured).
Users are advised to upgrade to Apache Log4j Core version 2.25.3, which addresses this issue.
As an alternative mitigation, the Socket Appender may be configured to use a private or restricted trust root to limit the set of trusted certificates.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-297 - Improper Validation of Certificate with Host Mismatch
Assigner
References
8 references
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Apache Software Foundation | Apache Log4j Core |
Affected:
2.0-beta9 , < 2.25.3
(maven)
Affected: 3.0.0-alpha1 , ≤ 3.0.0-beta3 (maven) cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:* |
Credits
Samuli Leinonen
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2025-68161",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-12-18T21:34:24.735166Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2025-12-18T21:46:19.782Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
},
{
"providerMetadata": {
"dateUpdated": "2026-01-20T00:13:44.911Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"url": "http://www.openwall.com/lists/oss-security/2025/12/18/1"
},
{
"url": "https://lists.debian.org/debian-lts-announce/2026/01/msg00015.html"
}
],
"title": "CVE Program Container"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://repo.maven.apache.org/maven2",
"cpes": [
"cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"packageName": "org.apache.logging.log4j:log4j-core",
"packageURL": "pkg:maven/org.apache.logging.log4j/log4j-core",
"product": "Apache Log4j Core",
"vendor": "Apache Software Foundation",
"versions": [
{
"lessThan": "2.25.3",
"status": "affected",
"version": "2.0-beta9",
"versionType": "maven"
},
{
"lessThanOrEqual": "3.0.0-beta3",
"status": "affected",
"version": "3.0.0-alpha1",
"versionType": "maven"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Samuli Leinonen"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eThe Socket Appender in Apache Log4j Core versions \u003ccode\u003e2.0-beta9\u003c/code\u003e through \u003ccode\u003e2.25.2\u003c/code\u003e does not perform TLS hostname verification of the peer certificate, even when the \u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName\"\u003everifyHostName\u003c/a\u003e configuration attribute or the \u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName\"\u003elog4j2.sslVerifyHostName\u003c/a\u003e system property is set to \u003ccode\u003etrue\u003c/code\u003e.\u003c/p\u003e\u003cp\u003eThis issue may allow a man-in-the-middle attacker to intercept or redirect log traffic under the following conditions:\u003c/p\u003e\u003cul\u003e\u003cli\u003eThe attacker is able to intercept or redirect network traffic between the client and the log receiver.\u003c/li\u003e\u003cli\u003eThe attacker can present a server certificate issued by a certification authority trusted by the Socket Appender\u2019s configured \u003cstrong\u003etrust store\u003c/strong\u003e (or by the default Java trust store if no custom trust store is configured).\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eUsers are advised to upgrade to Apache Log4j Core version \u003ccode\u003e2.25.3\u003c/code\u003e, which addresses this issue.\u003c/p\u003e\u003cp\u003eAs an alternative mitigation, the Socket Appender may be configured to use a private or restricted trust root to limit the set of trusted certificates.\u003c/p\u003e"
}
],
"value": "The Socket Appender in Apache Log4j Core versions 2.0-beta9 through 2.25.2 does not perform TLS hostname verification of the peer certificate, even when the verifyHostName https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName configuration attribute or the log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName system property is set to true.\n\nThis issue may allow a man-in-the-middle attacker to intercept or redirect log traffic under the following conditions:\n\n * The attacker is able to intercept or redirect network traffic between the client and the log receiver.\n * The attacker can present a server certificate issued by a certification authority trusted by the Socket Appender\u2019s configured trust store (or by the default Java trust store if no custom trust store is configured).\n\n\nUsers are advised to upgrade to Apache Log4j Core version 2.25.3, which addresses this issue.\n\nAs an alternative mitigation, the Socket Appender may be configured to use a private or restricted trust root to limit the set of trusted certificates."
}
],
"metrics": [
{
"other": {
"content": {
"text": "moderate"
},
"type": "Textual description of severity"
}
},
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "HIGH",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 6.3,
"baseSeverity": "MEDIUM",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "LOW",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:L/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "LOW",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-297",
"description": "CWE-297 Improper Validation of Certificate with Host Mismatch",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-10T16:18:50.424Z",
"orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
"shortName": "apache"
},
"references": [
{
"tags": [
"patch"
],
"url": "https://github.com/apache/logging-log4j2/pull/4002"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://logging.apache.org/security.html#CVE-2025-68161"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://logging.apache.org/cyclonedx/vdr.xml"
},
{
"tags": [
"related"
],
"url": "https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName"
},
{
"tags": [
"related"
],
"url": "https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://lists.apache.org/thread/xr33kyxq3sl67lwb61ggvm1fzc8k7dvx"
}
],
"source": {
"discovery": "EXTERNAL"
},
"title": "Apache Log4j Core: Missing TLS hostname verification in Socket appender",
"x_generator": {
"engine": "Vulnogram 0.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
"assignerShortName": "apache",
"cveId": "CVE-2025-68161",
"datePublished": "2025-12-18T20:47:49.123Z",
"dateReserved": "2025-12-16T11:30:53.875Z",
"dateUpdated": "2026-04-10T16:18:50.424Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-34477 (GCVE-0-2026-34477)
Vulnerability from cvelistv5 – Published: 2026-04-10 15:36 – Updated: 2026-04-10 17:38
VLAI
EPSS
VEX
Title
Apache Log4j Core: verifyHostName attribute silently ignored in TLS configuration, allowing hostname verification bypass
Summary
The fix for CVE-2025-68161 https://logging.apache.org/security.html#CVE-2025-68161 was incomplete: it addressed hostname verification only when enabled via the log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName system property, but not when configured through the verifyHostName https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName attribute of the <Ssl> element.
Although the verifyHostName configuration attribute was introduced in Log4j Core 2.12.0, it was silently ignored in all versions through 2.25.3, leaving TLS connections vulnerable to interception regardless of the configured value.
A network-based attacker may be able to perform a man-in-the-middle attack when all of the following conditions are met:
* An SMTP, Socket, or Syslog appender is in use.
* TLS is configured via a nested <Ssl> element.
* The attacker can present a certificate issued by a CA trusted by the appender's configured trust store, or by the default Java trust store if none is configured.
This issue does not affect users of the HTTP appender, which uses a separate verifyHostname https://logging.apache.org/log4j/2.x/manual/appenders/network.html#HttpAppender-attr-verifyHostName attribute that was not subject to this bug and verifies host names by default.
Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-297 - Improper Validation of Certificate with Host Mismatch
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://github.com/apache/logging-log4j2/pull/4075 | patch |
| https://logging.apache.org/security.html#CVE-2026-34477 | vendor-advisory |
| https://logging.apache.org/cyclonedx/vdr.xml | vendor-advisory |
| https://logging.apache.org/log4j/2.x/manual/appen… | related |
| https://lists.apache.org/thread/lkx8cl46t2bvkcwfc… | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Apache Software Foundation | Apache Log4j Core |
Affected:
2.12.0 , < 2.25.4
(maven)
Affected: 3.0.0-alpha1 , ≤ 3.0.0-beta3 (maven) cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:* |
Credits
Samuli Leinonen (original reporter)
Naresh Kandula (independently)
Vitaly Simonovich (independently)
Raijuna (independently)
Danish Siddiqui (djvirus, independently)
Markus Magnuson (independently)
Haruki Oyama (Waseda University, independently)
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-34477",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-10T17:36:46.652477Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-10T17:38:57.154Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://repo.maven.apache.org/maven2",
"cpes": [
"cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"packageName": "org.apache.logging.log4j:log4j-core",
"packageURL": "pkg:maven/org.apache.logging.log4j/log4j-core",
"product": "Apache Log4j Core",
"vendor": "Apache Software Foundation",
"versions": [
{
"lessThan": "2.25.4",
"status": "affected",
"version": "2.12.0",
"versionType": "maven"
},
{
"lessThanOrEqual": "3.0.0-beta3",
"status": "affected",
"version": "3.0.0-alpha1",
"versionType": "maven"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Samuli Leinonen (original reporter)"
},
{
"lang": "en",
"type": "finder",
"value": "Naresh Kandula (independently)"
},
{
"lang": "en",
"type": "finder",
"value": "Vitaly Simonovich (independently)"
},
{
"lang": "en",
"type": "finder",
"value": "Raijuna (independently)"
},
{
"lang": "en",
"type": "finder",
"value": "Danish Siddiqui (djvirus, independently)"
},
{
"lang": "en",
"type": "finder",
"value": "Markus Magnuson (independently)"
},
{
"lang": "en",
"type": "finder",
"value": "Haruki Oyama (Waseda University, independently)"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eThe fix for \u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://logging.apache.org/security.html#CVE-2025-68161\"\u003eCVE-2025-68161\u003c/a\u003e was incomplete: it addressed hostname verification only when enabled via the \u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName\"\u003e\u003ccode\u003elog4j2.sslVerifyHostName\u003c/code\u003e\u003c/a\u003e system property, but not when configured through the \u003ccode\u003e\u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName\"\u003everifyHostName\u003c/a\u003e\u003c/code\u003e attribute of the \u003ccode\u003e\u0026lt;Ssl\u0026gt;\u003c/code\u003e element.\u003c/p\u003e\u003cp\u003eAlthough the \u003ccode\u003everifyHostName\u003c/code\u003e configuration attribute was introduced in Log4j Core 2.12.0, it was silently ignored in all versions through 2.25.3, leaving TLS connections vulnerable to interception regardless of the configured value.\u003c/p\u003e\u003cp\u003eA network-based attacker may be able to perform a man-in-the-middle attack when \u003cstrong\u003eall\u003c/strong\u003e of the following conditions are met:\u003c/p\u003e\u003col\u003e\u003cli\u003eAn SMTP, Socket, or Syslog appender is in use.\u003c/li\u003e\u003cli\u003eTLS is configured via a nested \u003ccode\u003e\u0026lt;Ssl\u0026gt;\u003c/code\u003e element.\u003c/li\u003e\u003cli\u003eThe attacker can present a certificate issued by a CA trusted by the appender\u0027s configured trust store, or by the default Java trust store if none is configured.\u003c/li\u003e\u003c/ol\u003e\u003cp\u003eThis issue does not affect users of the HTTP appender, which uses a separate \u003ccode\u003e\u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://logging.apache.org/log4j/2.x/manual/appenders/network.html#HttpAppender-attr-verifyHostName\"\u003everifyHostname\u003c/a\u003e\u003c/code\u003e attribute that was not subject to this bug and verifies host names by default.\u003c/p\u003e\u003cp\u003eUsers are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue.\u003c/p\u003e"
}
],
"value": "The fix for CVE-2025-68161 https://logging.apache.org/security.html#CVE-2025-68161 was incomplete: it addressed hostname verification only when enabled via the log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName system property, but not when configured through the verifyHostName https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName attribute of the \u003cSsl\u003e element.\n\nAlthough the verifyHostName configuration attribute was introduced in Log4j Core 2.12.0, it was silently ignored in all versions through 2.25.3, leaving TLS connections vulnerable to interception regardless of the configured value.\n\nA network-based attacker may be able to perform a man-in-the-middle attack when all of the following conditions are met:\n\n * An SMTP, Socket, or Syslog appender is in use.\n * TLS is configured via a nested \u003cSsl\u003e element.\n * The attacker can present a certificate issued by a CA trusted by the appender\u0027s configured trust store, or by the default Java trust store if none is configured.\nThis issue does not affect users of the HTTP appender, which uses a separate verifyHostname https://logging.apache.org/log4j/2.x/manual/appenders/network.html#HttpAppender-attr-verifyHostName attribute that was not subject to this bug and verifies host names by default.\n\nUsers are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue."
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "HIGH",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 6.3,
"baseSeverity": "MEDIUM",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "LOW",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:L/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "LOW",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
},
{
"other": {
"content": {
"text": "moderate"
},
"type": "Textual description of severity"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-297",
"description": "CWE-297 Improper Validation of Certificate with Host Mismatch",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-10T15:36:19.740Z",
"orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
"shortName": "apache"
},
"references": [
{
"tags": [
"patch"
],
"url": "https://github.com/apache/logging-log4j2/pull/4075"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://logging.apache.org/security.html#CVE-2026-34477"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://logging.apache.org/cyclonedx/vdr.xml"
},
{
"tags": [
"related"
],
"url": "https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://lists.apache.org/thread/lkx8cl46t2bvkcwfcb2pd43ygc097lq4"
}
],
"source": {
"discovery": "EXTERNAL"
},
"timeline": [
{
"lang": "en",
"time": "2025-12-20T19:05:00.000Z",
"value": "Vulnerability reported by Samuli Leinonen"
},
{
"lang": "en",
"time": "2025-12-30T22:57:00.000Z",
"value": "Candidate patch shared internally by Piotr P. Karwasz"
},
{
"lang": "en",
"time": "2026-02-25T19:35:00.000Z",
"value": "Independent report received from Naresh Kandula"
},
{
"lang": "en",
"time": "2026-03-01T23:01:00.000Z",
"value": "Independent report received from Vitaly Simonovich"
},
{
"lang": "en",
"time": "2026-03-02T06:31:00.000Z",
"value": "Independent report received from Raijuna"
},
{
"lang": "en",
"time": "2026-03-08T18:17:00.000Z",
"value": "Independent report received from Danish Siddiqui"
},
{
"lang": "en",
"time": "2026-03-19T09:46:00.000Z",
"value": "Independent report received from Markus Magnuson"
},
{
"lang": "en",
"time": "2026-03-21T11:13:00.000Z",
"value": "Independent report received from Haruki Oyama"
},
{
"lang": "en",
"time": "2026-03-24T19:46:00.000Z",
"value": "Fix shared publicly by Piotr P. Karwasz as pull request #4075"
},
{
"lang": "en",
"time": "2026-03-28T11:19:00.000Z",
"value": "Log4j 2.25.4 released"
}
],
"title": "Apache Log4j Core: verifyHostName attribute silently ignored in TLS configuration, allowing hostname verification bypass",
"x_generator": {
"engine": "Vulnogram 0.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
"assignerShortName": "apache",
"cveId": "CVE-2026-34477",
"datePublished": "2026-04-10T15:36:19.740Z",
"dateReserved": "2026-03-28T11:26:04.052Z",
"dateUpdated": "2026-04-10T17:38:57.154Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-34478 (GCVE-0-2026-34478)
Vulnerability from cvelistv5 – Published: 2026-04-10 15:40 – Updated: 2026-04-10 17:50
VLAI
EPSS
VEX
Title
Apache Log4j Core: Log injection in Rfc5424Layout due to silent configuration incompatibility
Summary
Apache Log4j Core's Rfc5424Layout https://logging.apache.org/log4j/2.x/manual/layouts.html#RFC5424Layout , in versions 2.21.0 through 2.25.3, is vulnerable to log injection via CRLF sequences due to undocumented renames of security-relevant configuration attributes.
Two distinct issues affect users of stream-based syslog services who configure Rfc5424Layout directly:
* The newLineEscape attribute was silently renamed, causing newline escaping to stop working for users of TCP framing (RFC 6587), exposing them to CRLF injection in log output.
* The useTlsMessageFormat attribute was silently renamed, causing users of TLS framing (RFC 5425) to be silently downgraded to unframed TCP (RFC 6587), without newline escaping.
Users of the SyslogAppender are not affected, as its configuration attributes were not modified.
Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
Assigner
References
6 references
| URL | Tags |
|---|---|
| https://github.com/apache/logging-log4j2/pull/4074 | patch |
| https://logging.apache.org/security.html#CVE-2026-34478 | vendor-advisory |
| https://logging.apache.org/cyclonedx/vdr.xml | vendor-advisory |
| https://logging.apache.org/log4j/2.x/manual/layou… | related |
| https://lists.apache.org/thread/3k1clr2l6vkdnl4cb… | vendor-advisory |
| http://www.openwall.com/lists/oss-security/2026/04/10/7 |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Apache Software Foundation | Apache Log4j Core |
Affected:
2.21.0 , < 2.25.4
(maven)
Affected: 3.0.0-beta1 , ≤ 3.0.0-beta3 (maven) cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:* |
Credits
Samuli Leinonen
{
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2026-04-10T16:18:17.528Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"url": "http://www.openwall.com/lists/oss-security/2026/04/10/7"
}
],
"title": "CVE Program Container"
},
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-34478",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-10T17:48:27.852992Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-10T17:50:12.484Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://repo.maven.apache.org/maven2",
"cpes": [
"cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"packageName": "org.apache.logging.log4j:log4j-core",
"packageURL": "pkg:maven/org.apache.logging.log4j/log4j-core",
"product": "Apache Log4j Core",
"vendor": "Apache Software Foundation",
"versions": [
{
"lessThan": "2.25.4",
"status": "affected",
"version": "2.21.0",
"versionType": "maven"
},
{
"lessThanOrEqual": "3.0.0-beta3",
"status": "affected",
"version": "3.0.0-beta1",
"versionType": "maven"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Samuli Leinonen"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eApache Log4j Core\u0027s \u003ccode\u003e\u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://logging.apache.org/log4j/2.x/manual/layouts.html#RFC5424Layout\"\u003eRfc5424Layout\u003c/a\u003e\u003c/code\u003e, in versions 2.21.0 through 2.25.3, is vulnerable to log injection via CRLF sequences due to undocumented renames of security-relevant configuration attributes.\u003c/p\u003e\u003cp\u003eTwo distinct issues affect users of stream-based syslog services who configure \u003ccode\u003eRfc5424Layout\u003c/code\u003e directly:\u003c/p\u003e\u003cul\u003e\u003cli\u003eThe \u003ccode\u003enewLineEscape\u003c/code\u003e attribute was silently renamed, causing newline escaping to stop working for users of TCP framing (RFC 6587), exposing them to CRLF injection in log output.\u003c/li\u003e\u003cli\u003eThe \u003ccode\u003euseTlsMessageFormat\u003c/code\u003e attribute was silently renamed, causing users of TLS framing (RFC 5425) to be silently downgraded to unframed TCP (RFC 6587), without newline escaping.\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eUsers of the \u003ccode\u003eSyslogAppender\u003c/code\u003e are not affected, as its configuration attributes were not modified.\u003c/p\u003e\u003cp\u003eUsers are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue.\u003c/p\u003e"
}
],
"value": "Apache Log4j Core\u0027s Rfc5424Layout https://logging.apache.org/log4j/2.x/manual/layouts.html#RFC5424Layout , in versions 2.21.0 through 2.25.3, is vulnerable to log injection via CRLF sequences due to undocumented renames of security-relevant configuration attributes.\n\nTwo distinct issues affect users of stream-based syslog services who configure Rfc5424Layout directly:\n\n * The newLineEscape attribute was silently renamed, causing newline escaping to stop working for users of TCP framing (RFC 6587), exposing them to CRLF injection in log output.\n * The useTlsMessageFormat attribute was silently renamed, causing users of TLS framing (RFC 5425) to be silently downgraded to unframed TCP (RFC 6587), without newline escaping.\n\n\nUsers of the SyslogAppender are not affected, as its configuration attributes were not modified.\n\nUsers are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue."
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 6.9,
"baseSeverity": "MEDIUM",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "LOW",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
},
{
"other": {
"content": {
"text": "moderate"
},
"type": "Textual description of severity"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-684",
"description": "CWE-684 Incorrect Provision of Specified Functionality",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-117",
"description": "CWE-117 Improper Output Neutralization for Logs",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-10T15:40:17.713Z",
"orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
"shortName": "apache"
},
"references": [
{
"tags": [
"patch"
],
"url": "https://github.com/apache/logging-log4j2/pull/4074"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://logging.apache.org/security.html#CVE-2026-34478"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://logging.apache.org/cyclonedx/vdr.xml"
},
{
"tags": [
"related"
],
"url": "https://logging.apache.org/log4j/2.x/manual/layouts.html#RFC5424Layout"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://lists.apache.org/thread/3k1clr2l6vkdnl4cbhjrnt1nyjvb5gwt"
}
],
"source": {
"discovery": "EXTERNAL"
},
"timeline": [
{
"lang": "en",
"time": "2025-12-25T12:58:00.000Z",
"value": "Vulnerability reported by Samuli Leinonen"
},
{
"lang": "en",
"time": "2026-03-10T16:00:00.000Z",
"value": "Candidate patch shared internally by Piotr P. Karwasz"
},
{
"lang": "en",
"time": "2026-03-24T18:41:00.000Z",
"value": "Fix shared publicly by Piotr P. Karwasz as pull request #4074"
},
{
"lang": "en",
"time": "2026-03-25T11:02:00.000Z",
"value": "Fix verified by reporter"
},
{
"lang": "en",
"time": "2026-03-28T11:19:00.000Z",
"value": "Log4j 2.25.4 released"
}
],
"title": "Apache Log4j Core: Log injection in Rfc5424Layout due to silent configuration incompatibility",
"x_generator": {
"engine": "Vulnogram 0.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
"assignerShortName": "apache",
"cveId": "CVE-2026-34478",
"datePublished": "2026-04-10T15:40:17.713Z",
"dateReserved": "2026-03-28T13:17:35.586Z",
"dateUpdated": "2026-04-10T17:50:12.484Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-34479 (GCVE-0-2026-34479)
Vulnerability from cvelistv5 – Published: 2026-04-10 15:41 – Updated: 2026-04-10 17:47
VLAI
EPSS
VEX
Title
Apache Log4j 1 to Log4j 2 bridge: Silent log event loss in Log4j1XmlLayout due to unescaped XML 1.0 forbidden characters
Summary
The Log4j1XmlLayout from the Apache Log4j 1-to-Log4j 2 bridge fails to escape characters forbidden by the XML 1.0 standard, producing malformed XML output. Conforming XML parsers are required to reject documents containing such characters with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records.
Two groups of users are affected:
* Those using Log4j1XmlLayout directly in a Log4j Core 2 configuration file.
* Those using the Log4j 1 configuration compatibility layer with org.apache.log4j.xml.XMLLayout specified as the layout class.
Users are advised to upgrade to Apache Log4j 1-to-Log4j 2 bridge version 2.25.4, which corrects this issue.
Note: The Apache Log4j 1-to-Log4j 2 bridge is deprecated and will not be present in Log4j 3. Users are encouraged to consult the Log4j 1 to Log4j 2 migration guide https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html , and specifically the section on eliminating reliance on the bridge.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-116 - Improper Encoding or Escaping of Output
Assigner
References
6 references
| URL | Tags |
|---|---|
| https://github.com/apache/logging-log4j2/pull/4078 | patch |
| https://logging.apache.org/security.html#CVE-2026-34479 | vendor-advisory |
| https://logging.apache.org/cyclonedx/vdr.xml | vendor-advisory |
| https://logging.apache.org/log4j/2.x/migrate-from… | related |
| https://lists.apache.org/thread/gd0hp6mj17rn3kj27… | vendor-advisory |
| http://www.openwall.com/lists/oss-security/2026/04/10/8 |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Apache Software Foundation | Apache Log4j 1 to Log4j 2 bridge |
Affected:
2.7 , < 2.25.4
(maven)
Affected: 3.0.0-alpha1 , ≤ 3.0.0-beta2 (maven) cpe:2.3:a:apache:log4j_1_2_api:*:*:*:*:*:*:*:* |
Credits
Ap4sh (Samy Medjahed) and Ethicxz (Eliott Laurie) (original reporters)
jabaltarik1 (independently)
{
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2026-04-10T16:18:18.699Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"url": "http://www.openwall.com/lists/oss-security/2026/04/10/8"
}
],
"title": "CVE Program Container"
},
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-34479",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-10T17:45:24.466114Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-10T17:47:34.402Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://repo.maven.apache.org/maven2",
"cpes": [
"cpe:2.3:a:apache:log4j_1_2_api:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"packageName": "org.apache.logging.log4j:log4j-1.2-api",
"packageURL": "pkg:maven/org.apache.logging.log4j/log4j-1.2-api",
"product": "Apache Log4j 1 to Log4j 2 bridge",
"vendor": "Apache Software Foundation",
"versions": [
{
"lessThan": "2.25.4",
"status": "affected",
"version": "2.7",
"versionType": "maven"
},
{
"lessThanOrEqual": "3.0.0-beta2",
"status": "affected",
"version": "3.0.0-alpha1",
"versionType": "maven"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Ap4sh (Samy Medjahed) and Ethicxz (Eliott Laurie) (original reporters)"
},
{
"lang": "en",
"type": "finder",
"value": "jabaltarik1 (independently)"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eThe \u003ccode\u003eLog4j1XmlLayout\u003c/code\u003e from the Apache Log4j 1-to-Log4j 2 bridge fails to escape characters forbidden by the XML 1.0 standard, producing malformed XML output. Conforming XML parsers are required to reject documents containing such characters with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records.\u003c/p\u003e\u003cp\u003eTwo groups of users are affected:\u003c/p\u003e\u003cul\u003e\u003cli\u003eThose using \u003ccode\u003eLog4j1XmlLayout\u003c/code\u003e directly in a Log4j Core 2 configuration file.\u003c/li\u003e\u003cli\u003eThose using the Log4j 1 configuration compatibility layer with \u003ccode\u003eorg.apache.log4j.xml.XMLLayout\u003c/code\u003e specified as the layout class.\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eUsers are advised to upgrade to Apache Log4j 1-to-Log4j 2 bridge version 2.25.4, which corrects this issue.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eNote:\u003c/strong\u003e The Apache Log4j 1-to-Log4j 2 bridge is deprecated and will not be present in Log4j 3. Users are encouraged to consult the \u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html\"\u003eLog4j 1 to Log4j 2 migration guide\u003c/a\u003e, and specifically the section on eliminating reliance on the bridge.\u003c/p\u003e"
}
],
"value": "The Log4j1XmlLayout from the Apache Log4j 1-to-Log4j 2 bridge fails to escape characters forbidden by the XML 1.0 standard, producing malformed XML output. Conforming XML parsers are required to reject documents containing such characters with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records.\n\nTwo groups of users are affected:\n\n * Those using Log4j1XmlLayout directly in a Log4j Core 2 configuration file.\n * Those using the Log4j 1 configuration compatibility layer with org.apache.log4j.xml.XMLLayout specified as the layout class.\n\n\nUsers are advised to upgrade to Apache Log4j 1-to-Log4j 2 bridge version 2.25.4, which corrects this issue.\n\nNote: The Apache Log4j 1-to-Log4j 2 bridge is deprecated and will not be present in Log4j 3. Users are encouraged to consult the Log4j 1 to Log4j 2 migration guide https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html , and specifically the section on eliminating reliance on the bridge."
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 6.9,
"baseSeverity": "MEDIUM",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "LOW",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
},
{
"other": {
"content": {
"text": "moderate"
},
"type": "Textual description of severity"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-116",
"description": "CWE-116 Improper Encoding or Escaping of Output",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-10T15:41:07.888Z",
"orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
"shortName": "apache"
},
"references": [
{
"tags": [
"patch"
],
"url": "https://github.com/apache/logging-log4j2/pull/4078"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://logging.apache.org/security.html#CVE-2026-34479"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://logging.apache.org/cyclonedx/vdr.xml"
},
{
"tags": [
"related"
],
"url": "https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://lists.apache.org/thread/gd0hp6mj17rn3kj279vgy4p7kd4zz5on"
}
],
"source": {
"discovery": "EXTERNAL"
},
"timeline": [
{
"lang": "en",
"time": "2026-02-16T17:11:00.000Z",
"value": "Vulnerability reported by Ap4sh and ethicxz"
},
{
"lang": "en",
"time": "2026-03-15T05:39:00.000Z",
"value": "Independent report received from jabaltarik1"
},
{
"lang": "en",
"time": "2026-03-24T18:56:00.000Z",
"value": "Fix shared publicly by Piotr P. Karwasz as pull request #4078"
},
{
"lang": "en",
"time": "2026-03-25T09:46:00.000Z",
"value": "Fix verified by reporter"
},
{
"lang": "en",
"time": "2026-03-28T11:19:00.000Z",
"value": "Log4j 2.25.4 released"
}
],
"title": "Apache Log4j 1 to Log4j 2 bridge: Silent log event loss in Log4j1XmlLayout due to unescaped XML 1.0 forbidden characters",
"x_generator": {
"engine": "Vulnogram 0.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
"assignerShortName": "apache",
"cveId": "CVE-2026-34479",
"datePublished": "2026-04-10T15:41:07.888Z",
"dateReserved": "2026-03-28T14:06:31.965Z",
"dateUpdated": "2026-04-10T17:47:34.402Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-34480 (GCVE-0-2026-34480)
Vulnerability from cvelistv5 – Published: 2026-04-10 15:42 – Updated: 2026-04-10 17:45
VLAI
EPSS
VEX
Title
Apache Log4j Core: Silent log event loss in XmlLayout due to unescaped XML 1.0 forbidden characters
Summary
Apache Log4j Core's XmlLayout https://logging.apache.org/log4j/2.x/manual/layouts.html#XmlLayout , in versions up to and including 2.25.3, fails to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/#charsets producing invalid XML output whenever a log message or MDC value contains such characters.
The impact depends on the StAX implementation in use:
* JRE built-in StAX: Forbidden characters are silently written to the output, producing malformed XML. Conforming parsers must reject such documents with a fatal error, which may cause downstream log-processing systems to drop the affected records.
* Alternative StAX implementations (e.g., Woodstox https://github.com/FasterXML/woodstox , a transitive dependency of the Jackson XML Dataformat module): An exception is thrown during the logging call, and the log event is never delivered to its intended appender, only to Log4j's internal status logger.
Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue by sanitizing forbidden characters before XML output.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-116 - Improper Encoding or Escaping of Output
Assigner
References
6 references
| URL | Tags |
|---|---|
| https://github.com/apache/logging-log4j2/pull/4077 | patch |
| https://logging.apache.org/security.html#CVE-2026-34480 | vendor-advisory |
| https://logging.apache.org/cyclonedx/vdr.xml | vendor-advisory |
| https://logging.apache.org/log4j/2.x/manual/layou… | related |
| https://lists.apache.org/thread/5x0hcnng0chhghp6j… | vendor-advisory |
| http://www.openwall.com/lists/oss-security/2026/04/10/9 |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Apache Software Foundation | Apache Log4j Core |
Affected:
2.0-alpha1 , < 2.25.4
(maven)
Affected: 3.0.0-alpha1 , ≤ 3.0.0-beta3 (maven) cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:* |
Credits
Ap4sh (Samy Medjahed) and Ethicxz (Eliott Laurie) (original reporters)
jabaltarik1 (independently)
{
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2026-04-10T16:18:19.775Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"url": "http://www.openwall.com/lists/oss-security/2026/04/10/9"
}
],
"title": "CVE Program Container"
},
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-34480",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-10T17:43:51.255638Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-04-10T17:45:07.434Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://repo.maven.apache.org/maven2",
"cpes": [
"cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"packageName": "org.apache.logging.log4j:log4j-core",
"packageURL": "pkg:maven/org.apache.logging.log4j/log4j-core",
"product": "Apache Log4j Core",
"vendor": "Apache Software Foundation",
"versions": [
{
"lessThan": "2.25.4",
"status": "affected",
"version": "2.0-alpha1",
"versionType": "maven"
},
{
"lessThanOrEqual": "3.0.0-beta3",
"status": "affected",
"version": "3.0.0-alpha1",
"versionType": "maven"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Ap4sh (Samy Medjahed) and Ethicxz (Eliott Laurie) (original reporters)"
},
{
"lang": "en",
"type": "finder",
"value": "jabaltarik1 (independently)"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eApache Log4j Core\u0027s \u003ccode\u003e\u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://logging.apache.org/log4j/2.x/manual/layouts.html#XmlLayout\"\u003eXmlLayout\u003c/a\u003e\u003c/code\u003e, in versions up to and including 2.25.3, fails to sanitize characters forbidden by the \u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://www.w3.org/TR/xml/#charsets\"\u003eXML 1.0 specification\u003c/a\u003e producing invalid XML output whenever a log message or MDC value contains such characters.\u003c/p\u003e\u003cp\u003eThe impact depends on the StAX implementation in use:\u003c/p\u003e\u003cul\u003e\u003cli\u003e\u003cstrong\u003eJRE built-in StAX:\u003c/strong\u003e Forbidden characters are silently written to the output, producing malformed XML. Conforming parsers must reject such documents with a fatal error, which may cause downstream log-processing systems to drop the affected records.\u003c/li\u003e\u003cli\u003e\u003cstrong\u003eAlternative StAX implementations\u003c/strong\u003e (e.g., \u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://github.com/FasterXML/woodstox\"\u003eWoodstox\u003c/a\u003e, a transitive dependency of the Jackson XML Dataformat module): An exception is thrown during the logging call, and the log event is never delivered to its intended appender, only to Log4j\u0027s internal status logger.\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eUsers are advised to upgrade to Apache Log4j Core \u003ccode\u003e2.25.4\u003c/code\u003e, which corrects this issue by sanitizing forbidden characters before XML output.\u003c/p\u003e"
}
],
"value": "Apache Log4j Core\u0027s XmlLayout https://logging.apache.org/log4j/2.x/manual/layouts.html#XmlLayout , in versions up to and including 2.25.3, fails to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/#charsets producing invalid XML output whenever a log message or MDC value contains such characters.\n\nThe impact depends on the StAX implementation in use:\n\n * JRE built-in StAX: Forbidden characters are silently written to the output, producing malformed XML. Conforming parsers must reject such documents with a fatal error, which may cause downstream log-processing systems to drop the affected records.\n * Alternative StAX implementations (e.g., Woodstox https://github.com/FasterXML/woodstox , a transitive dependency of the Jackson XML Dataformat module): An exception is thrown during the logging call, and the log event is never delivered to its intended appender, only to Log4j\u0027s internal status logger.\n\n\nUsers are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue by sanitizing forbidden characters before XML output."
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 6.9,
"baseSeverity": "MEDIUM",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "LOW",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
},
{
"other": {
"content": {
"text": "moderate"
},
"type": "Textual description of severity"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-116",
"description": "CWE-116 Improper Encoding or Escaping of Output",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-10T15:42:03.843Z",
"orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
"shortName": "apache"
},
"references": [
{
"tags": [
"patch"
],
"url": "https://github.com/apache/logging-log4j2/pull/4077"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://logging.apache.org/security.html#CVE-2026-34480"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://logging.apache.org/cyclonedx/vdr.xml"
},
{
"tags": [
"related"
],
"url": "https://logging.apache.org/log4j/2.x/manual/layouts.html#XmlLayout"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://lists.apache.org/thread/5x0hcnng0chhghp6jgjdp3qmbbhfjzhb"
}
],
"source": {
"discovery": "EXTERNAL"
},
"timeline": [
{
"lang": "en",
"time": "2026-02-16T17:11:00.000Z",
"value": "Vulnerability reported by Ap4sh and ethicxz"
},
{
"lang": "en",
"time": "2026-03-10T20:15:00.000Z",
"value": "Candidate patch shared internally by Piotr P. Karwasz"
},
{
"lang": "en",
"time": "2026-03-15T05:39:00.000Z",
"value": "Independent report received from jabaltarik1"
},
{
"lang": "en",
"time": "2026-03-24T18:52:00.000Z",
"value": "Fix shared publicly by Piotr P. Karwasz as pull request #4077"
},
{
"lang": "en",
"time": "2026-03-25T09:46:00.000Z",
"value": "Fix verified by reporter"
},
{
"lang": "en",
"time": "2026-03-28T11:19:00.000Z",
"value": "Log4j 2.25.4 released"
}
],
"title": "Apache Log4j Core: Silent log event loss in XmlLayout due to unescaped XML 1.0 forbidden characters",
"x_generator": {
"engine": "Vulnogram 0.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
"assignerShortName": "apache",
"cveId": "CVE-2026-34480",
"datePublished": "2026-04-10T15:42:03.843Z",
"dateReserved": "2026-03-28T15:29:27.095Z",
"dateUpdated": "2026-04-10T17:45:07.434Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Trend slope:
-
(linear fit over daily sighting counts)
Show additional events:
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
Loading…
Loading…