CWE-116
Allowed-with-ReviewImproper Encoding or Escaping of Output
Abstraction: Class · Status: Draft
The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.
612 vulnerabilities reference this CWE, most recent first.
GHSA-F83R-Q8F4-F336
Vulnerability from github – Published: 2026-06-25 15:31 – Updated: 2026-06-25 15:31An attacker sending a large number of crafted DNS queries might be able to trigger a dynamic block being inserted with a value causing invalid output to be produced in the prometheus endpoint. The prometheus endpoint will then be rejected by the scraper until the dynamic block expires.
{
"affected": [],
"aliases": [
"CVE-2026-40011"
],
"database_specific": {
"cwe_ids": [
"CWE-116"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-25T13:16:39Z",
"severity": "LOW"
},
"details": "An attacker sending a large number of crafted DNS queries might be able to trigger a dynamic block being inserted with a value causing invalid output to be produced in the prometheus endpoint. The prometheus endpoint will then be rejected by the scraper until the dynamic block expires.",
"id": "GHSA-f83r-q8f4-f336",
"modified": "2026-06-25T15:31:59Z",
"published": "2026-06-25T15:31:59Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40011"
},
{
"type": "WEB",
"url": "https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-09.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-F98W-7CXR-FF2H
Vulnerability from github – Published: 2024-03-25 19:38 – Updated: 2024-03-25 22:32Impact
KaTeX users who render untrusted mathematical expressions could encounter malicious input using \includegraphics that runs arbitrary JavaScript, or generate invalid HTML.
Patches
Upgrade to KaTeX v0.16.10 to remove this vulnerability.
Workarounds
- Avoid use of or turn off the
trustoption, or set it to forbid\includegraphicscommands. - Forbid inputs containing the substring
"\\includegraphics". - Sanitize HTML output from KaTeX.
Details
\includegraphics did not properly quote its filename argument, allowing it to generate invalid or malicious HTML that runs scripts.
For more information
If you have any questions or comments about this advisory:
- Open an issue or security advisory in the KaTeX repository
- Email us at katex-security@mit.edu
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "katex"
},
"ranges": [
{
"events": [
{
"introduced": "0.11.0"
},
{
"fixed": "0.16.10"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-28245"
],
"database_specific": {
"cwe_ids": [
"CWE-116"
],
"github_reviewed": true,
"github_reviewed_at": "2024-03-25T19:38:34Z",
"nvd_published_at": "2024-03-25T20:15:08Z",
"severity": "MODERATE"
},
"details": "### Impact\nKaTeX users who render untrusted mathematical expressions could encounter malicious input using `\\includegraphics` that runs arbitrary JavaScript, or generate invalid HTML.\n\n### Patches\nUpgrade to KaTeX v0.16.10 to remove this vulnerability.\n\n### Workarounds\n* Avoid use of or turn off the `trust` option, or set it to forbid `\\includegraphics` commands.\n* Forbid inputs containing the substring `\"\\\\includegraphics\"`.\n* Sanitize HTML output from KaTeX.\n\n### Details\n`\\includegraphics` did not properly quote its filename argument, allowing it to generate invalid or malicious HTML that runs scripts.\n\n### For more information\nIf you have any questions or comments about this advisory:\n\n* Open an issue or security advisory in the [KaTeX repository](https://github.com/KaTeX/KaTeX/)\n* Email us at katex-security@mit.edu",
"id": "GHSA-f98w-7cxr-ff2h",
"modified": "2024-03-25T22:32:05Z",
"published": "2024-03-25T19:38:34Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/KaTeX/KaTeX/security/advisories/GHSA-f98w-7cxr-ff2h"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-28245"
},
{
"type": "WEB",
"url": "https://github.com/KaTeX/KaTeX/commit/c5897fcd1f73da9612a53e6b5544f1d776e17770"
},
{
"type": "PACKAGE",
"url": "https://github.com/KaTeX/KaTeX"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L",
"type": "CVSS_V3"
}
],
"summary": "KaTeX\u0027s `\\includegraphics` does not escape filename"
}
GHSA-FC6V-27MR-W8PC
Vulnerability from github – Published: 2025-04-11 18:31 – Updated: 2025-04-11 18:31Improper Encoding or Escaping of Output vulnerability in The Wikimedia Foundation Mediawiki - Version Compare Extension allows Cross-Site Scripting (XSS).This issue affects Mediawiki - Version Compare Extension: from 1.39 through 1.43.
{
"affected": [],
"aliases": [
"CVE-2025-32078"
],
"database_specific": {
"cwe_ids": [
"CWE-116"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-04-11T17:15:44Z",
"severity": "MODERATE"
},
"details": "Improper Encoding or Escaping of Output vulnerability in The Wikimedia Foundation Mediawiki - Version Compare Extension allows Cross-Site Scripting (XSS).This issue affects Mediawiki - Version Compare Extension: from 1.39 through 1.43.",
"id": "GHSA-fc6v-27mr-w8pc",
"modified": "2025-04-11T18:31:08Z",
"published": "2025-04-11T18:31:08Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-32078"
},
{
"type": "WEB",
"url": "https://gerrit.wikimedia.org/r/q/If901b3b98e615e1a4f4034d932d2d592000b51d0"
},
{
"type": "WEB",
"url": "https://phabricator.wikimedia.org/T384269"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/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",
"type": "CVSS_V4"
}
]
}
GHSA-FF77-26X5-69CR
Vulnerability from github – Published: 2025-04-28 21:30 – Updated: 2025-11-03 22:56Improper Neutralization of Escape, Meta, or Control Sequences vulnerability in Apache Tomcat. For a subset of unlikely rewrite rule configurations, it was possible for a specially crafted request to bypass some rewrite rules. If those rewrite rules effectively enforced security constraints, those constraints could be bypassed.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.5, from 10.1.0-M1 through 10.1.39, from 9.0.0.M1 through 9.0.102. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 though 8.5.100. Other, older, EOL versions may also be affected.
Users are recommended to upgrade to version 9.0.104, 10.1.40 or 11.0.6, which fix the issue.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 9.0.102"
},
"package": {
"ecosystem": "Maven",
"name": "org.apache.tomcat:tomcat-catalina"
},
"ranges": [
{
"events": [
{
"introduced": "9.0.76"
},
{
"fixed": "9.0.104"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.tomcat:tomcat-catalina"
},
"ranges": [
{
"events": [
{
"introduced": "10.1.10"
},
{
"fixed": "10.1.40"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.tomcat:tomcat-catalina"
},
"ranges": [
{
"events": [
{
"introduced": "11.0.0-M2"
},
{
"fixed": "11.0.6"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 9.0.102"
},
"package": {
"ecosystem": "Maven",
"name": "org.apache.tomcat.embed:tomcat-embed-core"
},
"ranges": [
{
"events": [
{
"introduced": "9.0.76"
},
{
"fixed": "9.0.104"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.tomcat.embed:tomcat-embed-core"
},
"ranges": [
{
"events": [
{
"introduced": "10.1.10"
},
{
"fixed": "10.1.40"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.tomcat.embed:tomcat-embed-core"
},
"ranges": [
{
"events": [
{
"introduced": "11.0.0-M2"
},
{
"fixed": "11.0.6"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.tomcat:tomcat-catalina"
},
"ranges": [
{
"events": [
{
"introduced": "8.5.0"
},
{
"last_affected": "8.5.100"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.tomcat.embed:tomcat-embed-core"
},
"ranges": [
{
"events": [
{
"introduced": "8.5.0"
},
{
"last_affected": "8.5.100"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-31651"
],
"database_specific": {
"cwe_ids": [
"CWE-116",
"CWE-150"
],
"github_reviewed": true,
"github_reviewed_at": "2025-04-29T15:03:25Z",
"nvd_published_at": "2025-04-28T20:15:20Z",
"severity": "LOW"
},
"details": "Improper Neutralization of Escape, Meta, or Control Sequences vulnerability in Apache Tomcat.\u00a0For a subset of unlikely rewrite rule configurations, it was possible for a specially crafted request to bypass some rewrite rules. If those rewrite rules effectively enforced security constraints, those constraints could be bypassed.\n\nThis issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.5, from 10.1.0-M1 through 10.1.39, from 9.0.0.M1 through 9.0.102. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 though 8.5.100. Other, older, EOL versions may also be affected.\n\nUsers are recommended to upgrade to version 9.0.104, 10.1.40 or 11.0.6, which fix the issue.",
"id": "GHSA-ff77-26x5-69cr",
"modified": "2025-11-03T22:56:57Z",
"published": "2025-04-28T21:30:43Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-31651"
},
{
"type": "WEB",
"url": "https://github.com/apache/tomcat/commit/066bf6b6a15a4e7e0941d4acf096841165b97098"
},
{
"type": "WEB",
"url": "https://github.com/apache/tomcat/commit/175dc75fc428930034a6c93fb52f830d955d8e64"
},
{
"type": "WEB",
"url": "https://github.com/apache/tomcat/commit/ee3ab548e92345eca0cbd1f01649eb36c6f29454"
},
{
"type": "WEB",
"url": "https://github.com/apache/tomcat/commit/fbecc915a10c5a3d634c5e2c6ced4ff479ce9953"
},
{
"type": "PACKAGE",
"url": "https://github.com/apache/tomcat"
},
{
"type": "WEB",
"url": "https://lists.apache.org/list.html?announce@tomcat.apache.org"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2025/07/msg00009.html"
},
{
"type": "WEB",
"url": "https://tomcat.apache.org/security-10.html"
},
{
"type": "WEB",
"url": "https://tomcat.apache.org/security-11.html"
},
{
"type": "WEB",
"url": "https://tomcat.apache.org/security-9.html"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2025/04/28/3"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U",
"type": "CVSS_V4"
}
],
"summary": "Apache Tomcat Rewrite rule bypass"
}
GHSA-FH88-2P7H-7G9H
Vulnerability from github – Published: 2022-02-10 00:00 – Updated: 2025-10-22 00:32An issue was discovered in the Calendar feature in Zimbra Collaboration Suite 8.8.x before 8.8.15 patch 30 (update 1), as exploited in the wild starting in December 2021. An attacker could place HTML containing executable JavaScript inside element attributes. This markup becomes unescaped, causing arbitrary markup to be injected into the document.
{
"affected": [],
"aliases": [
"CVE-2022-24682"
],
"database_specific": {
"cwe_ids": [
"CWE-116",
"CWE-79"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-02-09T04:15:00Z",
"severity": "MODERATE"
},
"details": "An issue was discovered in the Calendar feature in Zimbra Collaboration Suite 8.8.x before 8.8.15 patch 30 (update 1), as exploited in the wild starting in December 2021. An attacker could place HTML containing executable JavaScript inside element attributes. This markup becomes unescaped, causing arbitrary markup to be injected into the document.",
"id": "GHSA-fh88-2p7h-7g9h",
"modified": "2025-10-22T00:32:28Z",
"published": "2022-02-10T00:00:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-24682"
},
{
"type": "WEB",
"url": "https://blog.zimbra.com/2022/02/hotfix-available-5-feb-for-zero-day-exploit-vulnerability-in-zimbra-8-8-15"
},
{
"type": "WEB",
"url": "https://wiki.zimbra.com/wiki/Security_Center"
},
{
"type": "WEB",
"url": "https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P30"
},
{
"type": "WEB",
"url": "https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories"
},
{
"type": "WEB",
"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-24682"
},
{
"type": "WEB",
"url": "https://www.volexity.com/blog/2022/02/03/operation-emailthief-active-exploitation-of-zero-day-xss-vulnerability-in-zimbra"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-FJ9G-QQR2-C949
Vulnerability from github – Published: 2022-03-15 00:00 – Updated: 2022-03-22 00:00The Simple Quotation WordPress plugin through 1.3.2 does not have CSRF check when creating or editing a quote and does not sanitise and escape Quotes. As a result, attacker could make a logged in admin create or edit arbitrary quote, and put Cross-Site Scripting payloads in them
{
"affected": [],
"aliases": [
"CVE-2022-22734"
],
"database_specific": {
"cwe_ids": [
"CWE-116",
"CWE-352"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-03-14T15:15:00Z",
"severity": "MODERATE"
},
"details": "The Simple Quotation WordPress plugin through 1.3.2 does not have CSRF check when creating or editing a quote and does not sanitise and escape Quotes. As a result, attacker could make a logged in admin create or edit arbitrary quote, and put Cross-Site Scripting payloads in them",
"id": "GHSA-fj9g-qqr2-c949",
"modified": "2022-03-22T00:00:51Z",
"published": "2022-03-15T00:00:55Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-22734"
},
{
"type": "WEB",
"url": "https://wpscan.com/vulnerability/f6e15a23-8f8c-47c2-8227-e277856d8251"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-FJJ2-X466-W3HX
Vulnerability from github – Published: 2025-12-11 06:30 – Updated: 2025-12-11 06:30GitLab has remediated a security issue in GitLab CE/EE affecting all versions from 17.1 before 18.4.6, 18.5 before 18.5.4, and 18.6 before 18.6.2 that could have allowed an authenticated user to perform unauthorized actions on behalf of other users by injecting malicious HTML into vulnerability code flow displays.
{
"affected": [],
"aliases": [
"CVE-2025-8405"
],
"database_specific": {
"cwe_ids": [
"CWE-116"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-12-11T05:16:38Z",
"severity": "HIGH"
},
"details": "GitLab has remediated a security issue in GitLab CE/EE affecting all versions from 17.1 before 18.4.6, 18.5 before 18.5.4, and 18.6 before 18.6.2 that could have allowed an authenticated user to perform unauthorized actions on behalf of other users by injecting malicious HTML into vulnerability code flow displays.",
"id": "GHSA-fjj2-x466-w3hx",
"modified": "2025-12-11T06:30:24Z",
"published": "2025-12-11T06:30:24Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-8405"
},
{
"type": "WEB",
"url": "https://hackerone.com/reports/3270940"
},
{
"type": "WEB",
"url": "https://about.gitlab.com/releases/2025/12/10/patch-release-gitlab-18-6-2-released"
},
{
"type": "WEB",
"url": "https://gitlab.com/gitlab-org/gitlab/-/issues/558214"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-FMQW-7CGW-C6Q8
Vulnerability from github – Published: 2022-05-07 00:00 – Updated: 2022-05-14 00:01IBM Guardium Data Encryption (GDE) 4.0.0 and 5.0.0 prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved. IBM X-Force ID: 213865.
{
"affected": [],
"aliases": [
"CVE-2021-39027"
],
"database_specific": {
"cwe_ids": [
"CWE-116"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-05-06T16:15:00Z",
"severity": "MODERATE"
},
"details": "IBM Guardium Data Encryption (GDE) 4.0.0 and 5.0.0 prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved. IBM X-Force ID: 213865.",
"id": "GHSA-fmqw-7cgw-c6q8",
"modified": "2022-05-14T00:01:18Z",
"published": "2022-05-07T00:00:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-39027"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/213865"
},
{
"type": "WEB",
"url": "https://www.ibm.com/support/pages/node/6582499"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-FQX6-693C-F55G
Vulnerability from github – Published: 2026-02-18 22:08 – Updated: 2026-02-20 16:48Summary
The unit parameter in Custom OID functionality lacks strip_tags() sanitization while other fields (name, oid, datatype) are sanitized. The unsanitized value is stored in the database and rendered without HTML escaping, allowing Stored XSS.
Details
Vulnerable Input Processing (includes/html/forms/customoid.inc.php lines 18-21):
$name = strip_tags((string) $_POST['name']); // line 18 - SANITIZED
$oid = strip_tags((string) $_POST['oid']); // line 19 - SANITIZED
$datatype = strip_tags((string) $_POST['datatype']); // line 20 - SANITIZED
$unit = $_POST['unit']; // line 21 - NOT SANITIZED!
Vulnerable Output (graphs/customoid.inc.php lines 13-20):
$customoid_unit = $customoid['customoid_unit']; // Retrieved from DB
$customoid_current = \LibreNMS\Util\Number::formatSi(...) . $customoid_unit;
echo "...$customoid_current..."; // ECHOED WITHOUT ESCAPING!
PoC
#!/usr/bin/env python3
"""
XSS test for LibreNMS Custom OID - unit parameter
"""
import html as html_module
import re
def strip_tags(value):
return re.sub(r'<[^>]*?>', '', str(value))
# Simulate form processing (customoid.inc.php lines 18-21)
test_inputs = {
'name': '<script>alert(1)</script>Test OID',
'oid': '1.3.6.1.4.1.2021.10.1.3.1',
'datatype': 'GAUGE',
'unit': '<script>alert("XSS")</script>',
}
name = strip_tags(test_inputs['name']) # Sanitized
oid = strip_tags(test_inputs['oid']) # Sanitized
datatype = strip_tags(test_inputs['datatype']) # Sanitized
unit = test_inputs['unit'] # NOT SANITIZED!
print("Input Processing Analysis:")
print(f" name (strip_tags): {name}")
print(f" oid (strip_tags): {oid}")
print(f" datatype (strip_tags): {datatype}")
print(f" unit (NO strip_tags): {unit}")
print()
print("*** VULNERABILITY: 'unit' parameter has NO strip_tags()! ***")
# Test XSS payloads
payloads = [
'<script>alert("XSS")</script>',
'<img src=x onerror=alert(1)>',
'<svg onload=alert(1)>',
]
print("\nXSS Payload Tests:")
for payload in payloads:
escaped = html_module.escape(payload)
has_xss = '<script>' in payload or 'onerror=' in payload.lower()
print(f" Payload: {payload}")
print(f" Raw (vulnerable): Contains executable code: {has_xss}")
print(f" Escaped (safe): {escaped}")
Expected Output
Input Processing Analysis:
name (strip_tags): alert(1)Test OID
oid (strip_tags): 1.3.6.1.4.1.2021.10.1.3.1
datatype (strip_tags): GAUGE
unit (NO strip_tags): <script>alert("XSS")</script>
*** VULNERABILITY: 'unit' parameter has NO strip_tags()! ***
Impact
- Attack Vector: User with device edit permissions sets malicious Unit value
- Exploitation: XSS payload stored in database, executes for all users viewing device graphs
- Consequences:
- Session hijacking via cookie theft
- Admin account takeover
- Malicious actions on behalf of victims
- Persistent attack affecting all users
- Affected Users: All LibreNMS installations with Custom OID feature
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "librenms/librenms"
},
"ranges": [
{
"events": [
{
"introduced": "24.10.0"
},
{
"fixed": "26.2.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-27016"
],
"database_specific": {
"cwe_ids": [
"CWE-116",
"CWE-79"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-18T22:08:15Z",
"nvd_published_at": "2026-02-20T02:16:55Z",
"severity": "MODERATE"
},
"details": "### Summary\nThe `unit` parameter in Custom OID functionality lacks `strip_tags()` sanitization while other fields (`name`, `oid`, `datatype`) are sanitized. The unsanitized value is stored in the database and rendered without HTML escaping, allowing Stored XSS.\n\n### Details\n**Vulnerable Input Processing (`includes/html/forms/customoid.inc.php` lines 18-21):**\n```php\n$name = strip_tags((string) $_POST[\u0027name\u0027]); // line 18 - SANITIZED\n$oid = strip_tags((string) $_POST[\u0027oid\u0027]); // line 19 - SANITIZED\n$datatype = strip_tags((string) $_POST[\u0027datatype\u0027]); // line 20 - SANITIZED\n$unit = $_POST[\u0027unit\u0027]; // line 21 - NOT SANITIZED!\n```\n\n**Vulnerable Output (`graphs/customoid.inc.php` lines 13-20):**\n```php\n$customoid_unit = $customoid[\u0027customoid_unit\u0027]; // Retrieved from DB\n$customoid_current = \\LibreNMS\\Util\\Number::formatSi(...) . $customoid_unit;\necho \"...$customoid_current...\"; // ECHOED WITHOUT ESCAPING!\n```\n\n### PoC\n\n```python\n#!/usr/bin/env python3\n\"\"\"\nXSS test for LibreNMS Custom OID - unit parameter\n\"\"\"\n\nimport html as html_module\nimport re\n\ndef strip_tags(value):\n return re.sub(r\u0027\u003c[^\u003e]*?\u003e\u0027, \u0027\u0027, str(value))\n\n# Simulate form processing (customoid.inc.php lines 18-21)\ntest_inputs = {\n \u0027name\u0027: \u0027\u003cscript\u003ealert(1)\u003c/script\u003eTest OID\u0027,\n \u0027oid\u0027: \u00271.3.6.1.4.1.2021.10.1.3.1\u0027,\n \u0027datatype\u0027: \u0027GAUGE\u0027,\n \u0027unit\u0027: \u0027\u003cscript\u003ealert(\"XSS\")\u003c/script\u003e\u0027,\n}\n\nname = strip_tags(test_inputs[\u0027name\u0027]) # Sanitized\noid = strip_tags(test_inputs[\u0027oid\u0027]) # Sanitized\ndatatype = strip_tags(test_inputs[\u0027datatype\u0027]) # Sanitized\nunit = test_inputs[\u0027unit\u0027] # NOT SANITIZED!\n\nprint(\"Input Processing Analysis:\")\nprint(f\" name (strip_tags): {name}\")\nprint(f\" oid (strip_tags): {oid}\")\nprint(f\" datatype (strip_tags): {datatype}\")\nprint(f\" unit (NO strip_tags): {unit}\")\nprint()\nprint(\"*** VULNERABILITY: \u0027unit\u0027 parameter has NO strip_tags()! ***\")\n\n# Test XSS payloads\npayloads = [\n \u0027\u003cscript\u003ealert(\"XSS\")\u003c/script\u003e\u0027,\n \u0027\u003cimg src=x onerror=alert(1)\u003e\u0027,\n \u0027\u003csvg onload=alert(1)\u003e\u0027,\n]\n\nprint(\"\\nXSS Payload Tests:\")\nfor payload in payloads:\n escaped = html_module.escape(payload)\n has_xss = \u0027\u003cscript\u003e\u0027 in payload or \u0027onerror=\u0027 in payload.lower()\n print(f\" Payload: {payload}\")\n print(f\" Raw (vulnerable): Contains executable code: {has_xss}\")\n print(f\" Escaped (safe): {escaped}\")\n```\n\n### Expected Output\n\n```\nInput Processing Analysis:\n name (strip_tags): alert(1)Test OID\n oid (strip_tags): 1.3.6.1.4.1.2021.10.1.3.1\n datatype (strip_tags): GAUGE\n unit (NO strip_tags): \u003cscript\u003ealert(\"XSS\")\u003c/script\u003e\n\n*** VULNERABILITY: \u0027unit\u0027 parameter has NO strip_tags()! ***\n```\n### Impact\n- **Attack Vector:** User with device edit permissions sets malicious Unit value\n- **Exploitation:** XSS payload stored in database, executes for all users viewing device graphs\n- **Consequences:**\n - Session hijacking via cookie theft\n - Admin account takeover\n - Malicious actions on behalf of victims\n - Persistent attack affecting all users\n- **Affected Users:** All LibreNMS installations with Custom OID feature",
"id": "GHSA-fqx6-693c-f55g",
"modified": "2026-02-20T16:48:24Z",
"published": "2026-02-18T22:08:15Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/librenms/librenms/security/advisories/GHSA-fqx6-693c-f55g"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27016"
},
{
"type": "WEB",
"url": "https://github.com/librenms/librenms/pull/19040"
},
{
"type": "WEB",
"url": "https://github.com/librenms/librenms/commit/3bea263e02441690c01dea7fa3fe6ffec94af335"
},
{
"type": "PACKAGE",
"url": "https://github.com/librenms/librenms"
},
{
"type": "WEB",
"url": "https://github.com/librenms/librenms/releases/tag/26.2.0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "LibreNMS has a Stored XSS in Custom OID - unit parameter missing strip_tags()"
}
GHSA-FVCQ-4X64-HQXR
Vulnerability from github – Published: 2024-06-11 21:12 – Updated: 2025-02-28 17:38Impact
There is a reflected cross-site scripting (XSS) issue in jupyter-server-proxy[1]. The /proxy endpoint accepts a host path segment in the format /proxy/<host>. When this endpoint is called with an invalid host value, jupyter-server-proxy replies with a response that includes the value of host, without sanitization [2]. A third-party actor can leverage this by sending a phishing link with an invalid host value containing custom JavaScript to a user. When the user clicks this phishing link, the browser renders the response of GET /proxy/<host>, which runs the custom JavaScript contained in host set by the actor.
As any arbitrary JavaScript can be run after the user clicks on a phishing link, this issue permits extensive access to the user's JupyterLab instance for an actor. This issue exists in the latest release of jupyter-server-proxy, currently v4.1.2.
Impacted versions: >=3.0.0,<=4.1.2
Patches
The patches are included in ==4.2.0 and ==3.2.4.
Workarounds
Server operators who are unable to upgrade can disable the jupyter-server-proxy extension with:
jupyter server extension disable jupyter-server-proxy
References
[1] : https://github.com/jupyterhub/jupyter-server-proxy/ [2] : https://github.com/jupyterhub/jupyter-server-proxy/blob/62a290f08750f7ae55a0c29ca339c9a39a7b2a7b/jupyter_server_proxy/handlers.py#L328
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "jupyter-server-proxy"
},
"ranges": [
{
"events": [
{
"introduced": "3.0.0"
},
{
"fixed": "3.2.4"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "PyPI",
"name": "jupyter-server-proxy"
},
"ranges": [
{
"events": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.2.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-35225"
],
"database_specific": {
"cwe_ids": [
"CWE-116",
"CWE-79"
],
"github_reviewed": true,
"github_reviewed_at": "2024-06-11T21:12:47Z",
"nvd_published_at": "2024-06-11T22:15:09Z",
"severity": "CRITICAL"
},
"details": "### Impact\n\nThere is a reflected cross-site scripting (XSS) issue in `jupyter-server-proxy`[1]. The `/proxy` endpoint accepts a `host` path segment in the format `/proxy/\u003chost\u003e`. When this endpoint is called with an invalid `host` value, `jupyter-server-proxy` replies with a response that includes the value of `host`, without sanitization [2]. A third-party actor can leverage this by sending a phishing link with an invalid `host` value containing custom JavaScript to a user. When the user clicks this phishing link, the browser renders the response of `GET /proxy/\u003chost\u003e`, which runs the custom JavaScript contained in `host` set by the actor.\nAs any arbitrary JavaScript can be run after the user clicks on a phishing link, this issue permits extensive access to the user\u0027s JupyterLab instance for an actor. This issue exists in the latest release of `jupyter-server-proxy`, currently `v4.1.2`.\n**Impacted versions:** `\u003e=3.0.0,\u003c=4.1.2`\n\n### Patches\n\nThe patches are included in `==4.2.0` and `==3.2.4`.\n\n### Workarounds\n\nServer operators who are unable to upgrade can disable the `jupyter-server-proxy` extension with:\n\n```\njupyter server extension disable jupyter-server-proxy\n```\n\n### References\n\n[1] : https://github.com/jupyterhub/jupyter-server-proxy/\n[2] : https://github.com/jupyterhub/jupyter-server-proxy/blob/62a290f08750f7ae55a0c29ca339c9a39a7b2a7b/jupyter_server_proxy/handlers.py#L328",
"id": "GHSA-fvcq-4x64-hqxr",
"modified": "2025-02-28T17:38:13Z",
"published": "2024-06-11T21:12:47Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/jupyterhub/jupyter-server-proxy/security/advisories/GHSA-fvcq-4x64-hqxr"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-35225"
},
{
"type": "WEB",
"url": "https://github.com/jupyterhub/jupyter-server-proxy/commit/7abc9dc5bbb0b4b440548a5375261b8b8192fc22"
},
{
"type": "WEB",
"url": "https://github.com/jupyterhub/jupyter-server-proxy/commit/ff78128087e73fb9d0909e1366f8bf051e8ea878"
},
{
"type": "PACKAGE",
"url": "https://github.com/jupyterhub/jupyter-server-proxy"
},
{
"type": "WEB",
"url": "https://github.com/jupyterhub/jupyter-server-proxy/blob/62a290f08750f7ae55a0c29ca339c9a39a7b2a7b/jupyter_server_proxy/handlers.py#L328"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/jupyter-server-proxy/PYSEC-2024-236.yaml"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Jupyter Server Proxy has a reflected XSS issue in host parameter"
}
Mitigation MIT-4.3
Strategy: Libraries or Frameworks
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, consider using the ESAPI Encoding control [REF-45] or a similar tool, library, or framework. These will help the programmer encode outputs in a manner less prone to error.
- Alternately, use built-in functions, but consider using wrappers in case those functions are discovered to have a vulnerability.
Mitigation MIT-27
Strategy: Parameterization
- If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
- For example, stored procedures can enforce database query structure and reduce the likelihood of SQL injection.
Mitigation
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages. Study all expected communication protocols and data representations to determine the required encoding strategies.
Mitigation
In some cases, input validation may be an important strategy when output encoding is not a complete solution. For example, you may be providing the same output that will be processed by multiple consumers that use different encodings or representations. In other cases, you may be required to allow user-supplied input to contain control information, such as limited HTML tags that support formatting in a wiki or bulletin board. When this type of requirement must be met, use an extremely strict allowlist to limit which control sequences can be used. Verify that the resulting syntactic structure is what you expect. Use your normal encoding methods for the remainder of the input.
Mitigation
Use input validation as a defense-in-depth measure to reduce the likelihood of output encoding errors (see CWE-20).
Mitigation
Fully specify which encodings are required by components that will be communicating with each other.
Mitigation
When exchanging data between components, ensure that both components are using the same character encoding. Ensure that the proper encoding is applied at each interface. Explicitly set the encoding you are using whenever the protocol allows you to do so.
CAPEC-104: Cross Zone Scripting
An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security.
CAPEC-73: User-Controlled Filename
An attack of this type involves an adversary inserting malicious characters (such as a XSS redirection) into a filename, directly or indirectly that is then used by the target software to generate HTML text or other potentially executable content. Many websites rely on user-generated content and dynamically build resources like files, filenames, and URL links directly from user supplied data. In this attack pattern, the attacker uploads code that can execute in the client browser and/or redirect the client browser to a site that the attacker owns. All XSS attack payload variants can be used to pass and exploit these vulnerabilities.
CAPEC-81: Web Server Logs Tampering
Web Logs Tampering attacks involve an attacker injecting, deleting or otherwise tampering with the contents of web logs typically for the purposes of masking other malicious behavior. Additionally, writing malicious data to log files may target jobs, filters, reports, and other agents that process the logs in an asynchronous attack pattern. This pattern of attack is similar to "Log Injection-Tampering-Forging" except that in this case, the attack is targeting the logs of the web server and not the application.
CAPEC-85: AJAX Footprinting
This attack utilizes the frequent client-server roundtrips in Ajax conversation to scan a system. While Ajax does not open up new vulnerabilities per se, it does optimize them from an attacker point of view. A common first step for an attacker is to footprint the target environment to understand what attacks will work. Since footprinting relies on enumeration, the conversational pattern of rapid, multiple requests and responses that are typical in Ajax applications enable an attacker to look for many vulnerabilities, well-known ports, network locations and so on. The knowledge gained through Ajax fingerprinting can be used to support other attacks, such as XSS.