Multiple Jenkins plugin flaws enable RCE, XSS and phishing

Executive Summary

Multiple plugin flaws enable remote code execution, information disclosure, unauthorized access, stored XSS and phishing via open redirect. Risk is rated Critical for government and business entities of all sizes due to potential compromise of build infrastructure and related assets.

Key Details

Affected Platform

Jenkins

Attack Surface

Recommended Action

Apply vendor patch

Affected Environment

Jenkins deployments using specific versions of Credentials Binding, GitHub, GitHub Branch Source, HTML Publisher, Matrix Authorization, Microsoft Entra ID and Script Security plugins. Exposure applies where these plugins are installed at or below the listed vulnerable versions and have not yet been updated to the fixed releases.

Operational Impact

Compromise of Jenkins nodes may allow manipulation of build pipelines, deployment artifacts and integration workflows used by critical business systems. Exploitation could undermine trust in build outputs, disrupt delivery, expose sensitive data and support lateral movement into connected environments.

Technical Root Cause

Issues include missing permission checks, path traversal on credential file names, unsafe deserialization, improper URL handling and unescaped user-controlled fields. These flaws in plugin input validation and authorization controls allow unintended file writes, arbitrary connections, type instantiation, XSS and redirects.

Recommended Mitigation

Upgrade all affected plugins to the fixed versions specified, following testing and standard change control, and maintain ongoing patch processes.
Apply least privilege for Jenkins roles and credentials, ensure secure network architecture around Jenkins, and use exploit protection and web filtering.

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Full Technical Report

Download the complete analysis, including detailed technical findings and references.

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References

Primary technical details and version information are provided in the Jenkins security advisory dated 29 April 2026. Consult the advisory and this report’s CVE list (CVE-2026-42519 through CVE-2026-42525) when scoping exposure and validating remediation.