Jenkins Security Advisory: Multiple High-Severity Vulnerabilities (RCE/CSRF/XSS) Fix Guide

Key information summary regarding vulnerabilities from the webpage screenshot: --- Vulnerability Overview The Jenkins security bulletin dated 2026-08-05 disclosed multiple high-severity vulnerabilities affecting the core and several plugins. The main issues include: Deserialization Bypass: The Remoting library failed to correctly apply the JEP-200 filter, allowing attackers to execute arbitrary code. Symlink Abuse: Symbolic links pointing to arbitrary paths can be created, enabling file writes or code execution. Path Traversal: File parameters lack path validation, allowing writes to arbitrary locations on the system. Case-Sensitivity Defect: Username/group name comparisons are case-insensitive, potentially leading to privilege escalation. Misuse of Configuration Instantiation: Users with Overall/Manage permissions can instantiate arbitrary configuration objects. Groovy Sandbox Bypass: The Multijob plugin allows execution of unsandboxed Groovy code. CSRF Vulnerabilities: Plugins such as Multijob and SCM-Manager do not validate POST requests, allowing malicious operations to be triggered. Missing Permissions: Several plugins (HCL AppScan, External Workspace Manager, Parameterized Remote Trigger, XML Job to Job DSL) do not check permissions, allowing enumeration of credentials or reading of workspaces. Timing Attacks: The Webhook Secret Credentials Provider plugin uses non-constant-time comparison, which can be broken using statistical methods. Stored XSS: The Qualys and Summary Display plugins fail to escape user input, allowing injection of malicious scripts. Credential Leakage: The Google Chat Notification plugin incorrectly uses system-level credentials. --- Affected Scope Core Components Jenkins 2.575 and earlier LTS 2.568.1 and earlier Affected Plugins and Versions --- Remediation Core Fixes Jenkins 2.576 and LTS 2.568.2 have resolved most of these vulnerabilities. Remoting library: Applied JEP-200 filter in the fallback path. Symlinks: Extraction of .tar/.tar.gz files containing valid null names is denied. Path Traversal: Improved file path recognition to prevent writing to arbitrary locations. Case-Sensitivity: Usernames/group names are compared in canonical form. Configuration Instantiation: Restricted to allow only administrators to instantiate specific types. Groovy Scripts: Integrated the Script Security plugin to enforce sandboxing. CSRF: POST requests are required, and permission checks are added. Missing Permissions: Appropriate permission checks have been added. Timing Attacks: Constant-time comparison functions are used. XSS: User input is escaped. Credential Leakage: Correct contexts are set for credential lookup. Plugin Fixes Multijob Plugin: ≥ 677.v7ffc23d6a_4c2 HCL AppScan Plugin: ≥ 1.8.4 SCM-Manager Plugin: ≥ 1.12.1 External Workspace Manager Plugin: ≥ 1.4.2 Webhook Secret Credentials Provider Plugin: ≥ 32.v09cb_522f0a_8 Parameterized Remote Trigger Plugin: No fix available (at time of bulletin) XML Job to Job DSL Plugin: No fix available (at time of bulletin) Qualys Container Scanning Connector Plugin: No fix available (at time of bulletin) Summary Display Plugin: No fix available (at time of bulletin) Google Chat Notification Plugin: No fix available (at time of bulletin) > Note: Some plugins currently have no fixes available; refer to the official bulletin for plans regarding future updates. --- POC / Exploit Code No specific POC or exploit code blocks were provided on the page. --- ✅ It is recommended to upgrade immediately to the latest stable or LTS version and verify that affected plugins have been updated.

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Jenkins Security Advisory: Multiple High-Severity Vulnerabilities (RCE/CSRF/XSS) Fix Guide