CVE-2026-19429 (GCVE-0-2026-19429)
Vulnerability from cvelistv5 – Published: 2026-08-10 12:07 – Updated: 2026-08-11 07:23
VLAI
EPSS
VEX
Title
Jenkins - FilePath.untarFrom() Symlink Target Validation Bypass and Blank-Name Check Bypass (Arbitrary File Read)
Summary
Jenkins FilePath.untarFrom() does not validate symlink targets in extracted TAR archives, even in versions patched for CVE-2026-33001 and CVE-2026-70427. An authenticated attacker with job configuration privileges can include a malicious archive in a build step that creates workspace symlinks pointing to arbitrary files on the Jenkins controller. By reading the secrets directory, the attacker obtains the cryptographic keys used to sign remember-me cookies, forges a valid administrator session cookie without any admin interaction, and gains access to the Script Console for remote code execution. Jenkins 2.576 is additionally affected by a bypass of the CVE-2026-70427 blank-name check via Unicode zero-width characters (U+200B, U+200C, U+200D, U+2060, U+00AD), which Java's String.isBlank() does not recognize as whitespace.
Severity
8.8 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://www.jenkins.io/security/advisory/2026-03-… | related |
| https://www.jenkins.io/security/advisory/2026-08-05/ | related |
| https://github.com/jenkinsci/jenkins | third-party-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Jenkins Project | Jenkins |
Affected:
1.0 , ≤ 2.576
(weekly)
Affected: 1.0 , ≤ 2.568.2 (LTS) |
Date Public
2026-08-10 12:00
Credits
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-19429",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-10T15:34:41.496974Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-08-10T18:21:50.651Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "affected",
"product": "Jenkins",
"vendor": "Jenkins Project",
"versions": [
{
"lessThanOrEqual": "2.576",
"status": "affected",
"version": "1.0",
"versionType": "weekly"
},
{
"lessThanOrEqual": "2.568.2",
"status": "affected",
"version": "1.0",
"versionType": "LTS"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Jamshed Yergashvoyev (CVE GUY | TuranSec)"
}
],
"datePublic": "2026-08-10T12:00:00.000Z",
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eJenkins \u003ccode\u003eFilePath.untarFrom()\u003c/code\u003e does not validate symlink targets in extracted TAR archives, even in versions patched for CVE-2026-33001 and CVE-2026-70427. An authenticated attacker with job configuration privileges can include a malicious archive in a build step that creates workspace symlinks pointing to arbitrary files on the Jenkins controller. By reading the secrets directory, the attacker obtains the cryptographic keys used to sign remember-me cookies, forges a valid administrator session cookie without any admin interaction, and gains access to the Script Console for remote code execution. Jenkins 2.576 is additionally affected by a bypass of the CVE-2026-70427 blank-name check via Unicode zero-width characters (\u003ccode\u003eU+200B\u003c/code\u003e, \u003ccode\u003eU+200C\u003c/code\u003e, \u003ccode\u003eU+200D\u003c/code\u003e, \u003ccode\u003eU+2060\u003c/code\u003e, \u003ccode\u003eU+00AD\u003c/code\u003e), which Java\u0027s \u003ccode\u003eString.isBlank()\u003c/code\u003e does not recognize as whitespace.\u003c/p\u003e"
}
],
"value": "Jenkins FilePath.untarFrom() does not validate symlink targets in extracted TAR archives, even in versions patched for CVE-2026-33001 and CVE-2026-70427. An authenticated attacker with job configuration privileges can include a malicious archive in a build step that creates workspace symlinks pointing to arbitrary files on the Jenkins controller. By reading the secrets directory, the attacker obtains the cryptographic keys used to sign remember-me cookies, forges a valid administrator session cookie without any admin interaction, and gains access to the Script Console for remote code execution. Jenkins 2.576 is additionally affected by a bypass of the CVE-2026-70427 blank-name check via Unicode zero-width characters (U+200B, U+200C, U+200D, U+2060, U+00AD), which Java\u0027s String.isBlank() does not recognize as whitespace."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
},
{
"cvssV4_0": {
"baseScore": 9.4,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
"version": "4.0"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-59",
"description": "CWE-59: Improper Link Resolution Before File Access (\u0027Link Following\u0027)",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-184",
"description": "CWE-184: Incomplete List of Disallowed Inputs",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-11T07:23:15.794Z",
"orgId": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
"shortName": "TuranSec"
},
"references": [
{
"name": "Jenkins Security Advisory 2026-03-18 (CVE-2026-33001 \u2014 incomplete fix)",
"tags": [
"related"
],
"url": "https://www.jenkins.io/security/advisory/2026-03-18/#SECURITY-3657"
},
{
"name": "Jenkins Security Advisory 2026-08-05 (CVE-2026-70427)",
"tags": [
"related"
],
"url": "https://www.jenkins.io/security/advisory/2026-08-05/"
},
{
"name": "Jenkins Source Repository",
"tags": [
"third-party-advisory"
],
"url": "https://github.com/jenkinsci/jenkins"
}
],
"source": {
"discovery": "EXTERNAL"
},
"timeline": [
{
"lang": "en",
"time": "2026-04-04T00:00:00.000Z",
"value": "Vulnerability discovered via patch-diff analysis of CVE-2026-33001 fix"
},
{
"lang": "en",
"time": "2026-08-05T00:00:00.000Z",
"value": "Re-verified against Jenkins 2.557 and LTS 2.555.3 \u2014 still unpatched"
},
{
"lang": "en",
"time": "2026-08-10T12:00:00.000Z",
"value": "Public disclosure (90-day window exceeded)"
},
{
"lang": "en",
"time": "2026-08-11T00:00:00.000Z",
"value": "Additional variant confirmed: CVE-2026-70427 blank-name patch bypass via Unicode zero-width characters (U+200B/U+200C/U+200D/U+2060/U+00AD) on Jenkins 2.576"
},
{
"lang": "en",
"time": "2026-08-11T08:00:00.000Z",
"value": "Full impact confirmed: secrets directory read enables remember-me cookie forgery and unauthenticated admin RCE with zero admin interaction"
}
],
"title": "Jenkins - FilePath.untarFrom() Symlink Target Validation Bypass and Blank-Name Check Bypass (Arbitrary File Read)"
}
},
"cveMetadata": {
"assignerOrgId": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
"assignerShortName": "TuranSec",
"cveId": "CVE-2026-19429",
"datePublished": "2026-08-10T12:07:02.996Z",
"dateReserved": "2026-08-10T12:06:37.123Z",
"dateUpdated": "2026-08-11T07:23:15.794Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-19429",
"date": "2026-08-11",
"epss": "0.00661",
"percentile": "0.48293"
},
"nvd": "{\"cve\":{\"id\":\"CVE-2026-19429\",\"sourceIdentifier\":\"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c\",\"published\":\"2026-08-10T13:17:58.940\",\"lastModified\":\"2026-08-11T08:17:20.723\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Jenkins FilePath.untarFrom() does not validate symlink targets in extracted TAR archives, even in versions patched for CVE-2026-33001 and CVE-2026-70427. An authenticated attacker with job configuration privileges can include a malicious archive in a build step that creates workspace symlinks pointing to arbitrary files on the Jenkins controller. By reading the secrets directory, the attacker obtains the cryptographic keys used to sign remember-me cookies, forges a valid administrator session cookie without any admin interaction, and gains access to the Script Console for remote code execution. Jenkins 2.576 is additionally affected by a bypass of the CVE-2026-70427 blank-name check via Unicode zero-width characters (U+200B, U+200C, U+200D, U+2060, U+00AD), which Java\u0027s String.isBlank() does not recognize as whitespace.\"}],\"affected\":[{\"source\":\"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c\",\"affectedData\":[{\"vendor\":\"Jenkins Project\",\"product\":\"Jenkins\",\"defaultStatus\":\"affected\",\"versions\":[{\"version\":\"1.0\",\"lessThanOrEqual\":\"2.576\",\"versionType\":\"weekly\",\"status\":\"affected\"},{\"version\":\"1.0\",\"lessThanOrEqual\":\"2.568.2\",\"versionType\":\"LTS\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X\",\"baseScore\":9.4,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"HIGH\",\"vulnIntegrityImpact\":\"HIGH\",\"vulnAvailabilityImpact\":\"HIGH\",\"subConfidentialityImpact\":\"HIGH\",\"subIntegrityImpact\":\"HIGH\",\"subAvailabilityImpact\":\"HIGH\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"cvssMetricV31\":[{\"source\":\"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":8.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":5.9}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-08-10T15:34:41.496974Z\",\"id\":\"CVE-2026-19429\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"total\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-59\"},{\"lang\":\"en\",\"value\":\"CWE-184\"}]}],\"references\":[{\"url\":\"https://github.com/jenkinsci/jenkins\",\"source\":\"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c\"},{\"url\":\"https://www.jenkins.io/security/advisory/2026-03-18/#SECURITY-3657\",\"source\":\"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c\"},{\"url\":\"https://www.jenkins.io/security/advisory/2026-08-05/\",\"source\":\"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c\"}]}}",
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-19429\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-08-10T15:34:41.496974Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-08-10T15:34:47.081Z\"}}], \"cna\": {\"title\": \"Jenkins - FilePath.untarFrom() Symlink Target Validation Bypass and Blank-Name Check Bypass (Arbitrary File Read)\", \"source\": {\"discovery\": \"EXTERNAL\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Jamshed Yergashvoyev (CVE GUY | TuranSec)\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV3_1\": {\"version\": \"3.1\", \"baseScore\": 8.8, \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}, {\"format\": \"CVSS\", \"cvssV4_0\": {\"version\": \"4.0\", \"baseScore\": 9.4, \"baseSeverity\": \"CRITICAL\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"vendor\": \"Jenkins Project\", \"product\": \"Jenkins\", \"versions\": [{\"status\": \"affected\", \"version\": \"1.0\", \"versionType\": \"weekly\", \"lessThanOrEqual\": \"2.576\"}, {\"status\": \"affected\", \"version\": \"1.0\", \"versionType\": \"LTS\", \"lessThanOrEqual\": \"2.568.2\"}], \"defaultStatus\": \"affected\"}], \"timeline\": [{\"lang\": \"en\", \"time\": \"2026-04-04T00:00:00.000Z\", \"value\": \"Vulnerability discovered via patch-diff analysis of CVE-2026-33001 fix\"}, {\"lang\": \"en\", \"time\": \"2026-08-05T00:00:00.000Z\", \"value\": \"Re-verified against Jenkins 2.557 and LTS 2.555.3 \\u2014 still unpatched\"}, {\"lang\": \"en\", \"time\": \"2026-08-10T12:00:00.000Z\", \"value\": \"Public disclosure (90-day window exceeded)\"}, {\"lang\": \"en\", \"time\": \"2026-08-11T00:00:00.000Z\", \"value\": \"Additional variant confirmed: CVE-2026-70427 blank-name patch bypass via Unicode zero-width characters (U+200B/U+200C/U+200D/U+2060/U+00AD) on Jenkins 2.576\"}, {\"lang\": \"en\", \"time\": \"2026-08-11T08:00:00.000Z\", \"value\": \"Full impact confirmed: secrets directory read enables remember-me cookie forgery and unauthenticated admin RCE with zero admin interaction\"}], \"datePublic\": \"2026-08-10T12:00:00.000Z\", \"references\": [{\"url\": \"https://www.jenkins.io/security/advisory/2026-03-18/#SECURITY-3657\", \"name\": \"Jenkins Security Advisory 2026-03-18 (CVE-2026-33001 \\u2014 incomplete fix)\", \"tags\": [\"related\"]}, {\"url\": \"https://www.jenkins.io/security/advisory/2026-08-05/\", \"name\": \"Jenkins Security Advisory 2026-08-05 (CVE-2026-70427)\", \"tags\": [\"related\"]}, {\"url\": \"https://github.com/jenkinsci/jenkins\", \"name\": \"Jenkins Source Repository\", \"tags\": [\"third-party-advisory\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Jenkins FilePath.untarFrom() does not validate symlink targets in extracted TAR archives, even in versions patched for CVE-2026-33001 and CVE-2026-70427. An authenticated attacker with job configuration privileges can include a malicious archive in a build step that creates workspace symlinks pointing to arbitrary files on the Jenkins controller. By reading the secrets directory, the attacker obtains the cryptographic keys used to sign remember-me cookies, forges a valid administrator session cookie without any admin interaction, and gains access to the Script Console for remote code execution. Jenkins 2.576 is additionally affected by a bypass of the CVE-2026-70427 blank-name check via Unicode zero-width characters (U+200B, U+200C, U+200D, U+2060, U+00AD), which Java\u0027s String.isBlank() does not recognize as whitespace.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eJenkins \u003ccode\u003eFilePath.untarFrom()\u003c/code\u003e does not validate symlink targets in extracted TAR archives, even in versions patched for CVE-2026-33001 and CVE-2026-70427. An authenticated attacker with job configuration privileges can include a malicious archive in a build step that creates workspace symlinks pointing to arbitrary files on the Jenkins controller. By reading the secrets directory, the attacker obtains the cryptographic keys used to sign remember-me cookies, forges a valid administrator session cookie without any admin interaction, and gains access to the Script Console for remote code execution. Jenkins 2.576 is additionally affected by a bypass of the CVE-2026-70427 blank-name check via Unicode zero-width characters (\u003ccode\u003eU+200B\u003c/code\u003e, \u003ccode\u003eU+200C\u003c/code\u003e, \u003ccode\u003eU+200D\u003c/code\u003e, \u003ccode\u003eU+2060\u003c/code\u003e, \u003ccode\u003eU+00AD\u003c/code\u003e), which Java\u0027s \u003ccode\u003eString.isBlank()\u003c/code\u003e does not recognize as whitespace.\u003c/p\u003e\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-59\", \"description\": \"CWE-59: Improper Link Resolution Before File Access (\u0027Link Following\u0027)\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-184\", \"description\": \"CWE-184: Incomplete List of Disallowed Inputs\"}]}], \"providerMetadata\": {\"orgId\": \"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c\", \"shortName\": \"TuranSec\", \"dateUpdated\": \"2026-08-11T07:23:15.794Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-19429\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-08-11T07:23:15.794Z\", \"dateReserved\": \"2026-08-10T12:06:37.123Z\", \"assignerOrgId\": \"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c\", \"datePublished\": \"2026-08-10T12:07:02.996Z\", \"assignerShortName\": \"TuranSec\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
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…