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Jenkins Security Advisory 2026-04-29

This advisory announces vulnerabilities in the following Jenkins deliverables:

Descriptions

Missing permission check in Script Security Plugin allows enumerating pending and approved classpaths

SECURITY-3662 / CVE-2026-42519
Severity (CVSS): Medium
Affected plugin: script-security
Description:

Script Security Plugin 1399.ve6a_66547f6e1 and earlier does not perform a permission check in an HTTP endpoint.

This allows attackers with Overall/Read permission to enumerate pending and approved Script Security classpaths.

Script Security Plugin 1402.v94c9ce464861 requires Overall/Administer permission to enumerate pending and approved Script Security classpaths.

This vulnerability has been reported through the Jenkins Bug Bounty Program sponsored by the European Commission.

Path traversal vulnerability in Credentials Binding Plugin

SECURITY-3672 / CVE-2026-42520
Severity (CVSS): High
Affected plugin: credentials-binding
Description:

Credentials Binding Plugin 719.v80e905ef14eb_ and earlier does not sanitize file names for file and zip file credentials.

This allows attackers able to provide credentials to a job to write files to arbitrary locations on the node filesystem. If Jenkins is configured to allow a low-privileged user to configure file or zip file credentials used for a job running on the built-in node, this can lead to remote code execution.

Credentials Binding Plugin 720.v3f6decef43ea_ sanitizes the file name provided for file and zip file credentials, preventing path traversal.

This vulnerability has been reported through the Jenkins Bug Bounty Program sponsored by the European Commission.

Unsafe deserialization allows invoking parameterless constructors in Matrix Authorization Strategy Plugin

SECURITY-3676 / CVE-2026-42521
Severity (CVSS): Medium
Affected plugin: matrix-auth
Description:

Matrix Authorization Strategy Plugin 2.0-beta-1 through 3.2.9 (both inclusive) invokes parameterless constructors of classes specified in configuration when deserializing inheritance strategies, without restricting the classes that can be instantiated.

This can be abused by attackers with Item/Configure permission to instantiate arbitrary types, which may lead to information disclosure or other impacts depending on the classes available on the classpath.

Matrix Authorization Strategy Plugin 3.2.10 verifies that the class being instantiated is an inheritance strategy implementation, preventing instantiation of arbitrary types.

This vulnerability has been reported through the Jenkins Bug Bounty Program sponsored by the European Commission.

Missing permission check in GitHub Branch Source Plugin allows performing a connection test

SECURITY-3702 / CVE-2026-42522
Severity (CVSS): Medium
Affected plugin: github-branch-source
Description:

GitHub Branch Source Plugin 1967.vdea_d580c1a_b_a_ and earlier does not perform a permission check in a method implementing form validation.

This allows attackers with Overall/Read permission to connect to an attacker-specified URL with attacker-specified GitHub App credentials.

GitHub Branch Source Plugin 1967.1969.v205fd594c821 requires Overall/Manage permission to perform the connection test.

This vulnerability has been reported through the Jenkins Bug Bounty Program sponsored by the European Commission.

XSS vulnerability in GitHub Plugin

SECURITY-3704 / CVE-2026-42523
Severity (CVSS): High
Affected plugin: github
Description:

GitHub Plugin 1.46.0 and earlier improperly processes the current job URL as part of JavaScript implementing validation of the feature "GitHub hook trigger for GITScm polling".

This results in a stored cross-site scripting (XSS) vulnerability exploitable by non-anonymous attackers with Overall/Read permission.

GitHub Plugin 1.46.0.1 no longer processes the current job URL as part of JavaScript implementing validation of the feature "GitHub hook trigger for GITScm polling".

This vulnerability has been reported through the Jenkins Bug Bounty Program sponsored by the European Commission.

XSS vulnerability in legacy wrapper file in HTML Publisher Plugin

SECURITY-3706 / CVE-2026-42524
Severity (CVSS): High
Affected plugin: htmlpublisher
Description:

HTML Publisher Plugin 427 and earlier does not escape job name and URL in the legacy wrapper file.

This results in a stored cross-site scripting (XSS) vulnerability exploitable by attackers with Item/Configure permission.

HTML Publisher Plugin 427.1 escapes job name and URL when generating the legacy wrapper file.

This fix only applies to newly generated wrappers.
On Jenkins 2.539 and newer, LTS 2.541.1 and newer, enforcing Content Security Policy protection mitigates this vulnerability.
This vulnerability has been reported through the Jenkins Bug Bounty Program sponsored by the European Commission.

Open redirect vulnerability in Microsoft Entra ID (previously Azure AD) Plugin

SECURITY-3760 / CVE-2026-42525
Severity (CVSS): Medium
Affected plugin: azure-ad
Description:

Microsoft Entra ID (previously Azure AD) Plugin 666.v6060de32f87d and earlier does not restrict the redirect URL after login.

This allows attackers to perform phishing attacks by having users go to a Jenkins URL that will forward them to a different site after successful authentication.

Microsoft Entra ID (previously Azure AD) Plugin 667.v4c5827a_e74a_0 only redirects to relative (Jenkins) URLs.

Severity

Affected Versions

  • Credentials Binding Plugin up to and including 719.v80e905ef14eb_
  • GitHub Plugin up to and including 1.46.0
  • GitHub Branch Source Plugin up to and including 1967.vdea_d580c1a_b_a_
  • HTML Publisher Plugin up to and including 427
  • Matrix Authorization Strategy Plugin up to and including 3.2.9
  • Microsoft Entra ID (previously Azure AD) Plugin up to and including 666.v6060de32f87d
  • Script Security Plugin up to and including 1399.ve6a_66547f6e1

Fix

  • Credentials Binding Plugin should be updated to version 720.v3f6decef43ea_
  • GitHub Plugin should be updated to version 1.46.0.1
  • GitHub Branch Source Plugin should be updated to version 1967.1969.v205fd594c821
  • HTML Publisher Plugin should be updated to version 427.1
  • Matrix Authorization Strategy Plugin should be updated to version 3.2.10
  • Microsoft Entra ID (previously Azure AD) Plugin should be updated to version 667.v4c5827a_e74a_0
  • Script Security Plugin should be updated to version 1402.v94c9ce464861

These versions include fixes to the vulnerabilities described above. All prior versions are considered to be affected by these vulnerabilities unless otherwise indicated.

Credit

The Jenkins project would like to thank the reporters for discovering and reporting these vulnerabilities:

  • Ap4sh - Samy Medjahed for SECURITY-3662, SECURITY-3702
  • Ap4sh - Samy Medjahed; and, independently, Dholland2022; and Muhamad Billy Sakti Baraja for SECURITY-3672
  • Arafat Ul Islam (elaichix), Cybersecurity Researcher, IUBAT, Bangladesh for SECURITY-3676
  • dqh1 for SECURITY-3704
  • dyingman1 (https://github.com/dyingman1, redpoc Offensive Security Team) for SECURITY-3760