The Jenkins project released Security Bulletin 2025-10-29 on October 28, 2025, disclosing multiple vulnerabilities in 13 plugins that support the popular open-source automation server.
See also: Jenkins security update fixes vulnerabilities in CI/CD Pipelines
These vulnerabilities range from high-severity authentication bypasses to permissions misconfigurations and credential exposure, potentially exposing enterprise CI/CD pipelines to unauthorized access and code execution.
While there are fixes for two critical issues in the SAML and MCP Server, most others remain unresolved, prompting immediate updates where possible and careful monitoring.
The announcement highlights a replay vulnerability in the SAML Plugin (SECURITY-3613, CVE-2025-64131), rated high severity with a CVSS score of 7.5. Versions up to 4.583.vc68232f7018a_ lack a replay cache, allowing attackers who intercept SAML authentication flows to replay requests and impersonate users. This could provide full access to Jenkins instances running sensitive builds, especially in federated environments using single sign-on. The fix in version 4.583.585.v22ccc1139f55 introduces a replay cache to block duplicates, a simple mitigation that administrators should prioritize.
Additionally, the MCP Server Plugin suffers from a lack of privilege checks (SECURITY-3622, CVE-2025-64132), a medium severity (CVSS 5.4) issue affecting versions up to 0.84.v50ca_24ef83f2. Attackers with basic Item/Read access can export SCM configurations, trigger unauthorized builds, or capture cloud settings without proper privileges via tools such as getJobScm, triggerBuild , and getStatus. This increases the risks in multi-user environments, allowing lateral movement within Jenkins. The update to version 0.86.v7d3355e6a_a_18 enforces these checks, effectively closing the gap.
See also: Jenkins fixes critical vulnerabilities in servers and plugins
Beyond these, the announcement reveals a cluster of medium to high severity vulnerabilities in other plugins, including CSRF and credential mishandling vulnerabilities. For example, the Extensible Choice Parameter Plugin (SECURITY-3583, CVE-2025-64133) exposes a CSRF endpoint (CVSS 4.3) that allows unauthenticated users to execute Groovy code in a sandbox via spoofed interactions, with no fix yet available. Similarly, the JDepend Plugin's outdated XML parser (SECURITY-2936, CVE-2025-64134, CVSS 7.1) allows XXE attacks to extract secrets or SSRF when processing crafted reports.
Credential storage issues plague several plugins: OpenShift Pipeline (CVE-2025-64143), ByteGuard Build Actions (CVE-2025-64144) , and Curseforge Publisher (CVE-2025-64146) store tokens or API keys in plain text within task config.xml files, visible to users with Extended Read access (CVSS 4.3 each). The azure-cli Plugin goes further with shell command injection (SECURITY-3538, CVE-2025-64140, CVSS 8.8), allowing arbitrary controller execution for those with Item/Configure permissions, with no available fix.
Plugins such as Themis, Start Windocks Containers, Nexus Task Runner , and Publish to Bitbucket also have CSRF and missing checks that could leak credentials or link to malicious URLs (CVSS 4.3–5.4). The Eggplant Runner Plugin disables a Java HTTP authentication protection (SECURITY-3326, CVE-2025-64135, CVSS 5.9), re-introducing vulnerabilities from CVE-2016-5597.
These vulnerabilities highlight the double-edged sword of Jenkins’ extensive plugin ecosystem: flexibility at the cost of security if not maintained. With over 1,800 plugins, unpatched instances on corporate networks could face exploit chains ranging from authentication bypasses to RCEs, amplifying supply chain threats to software development.
See also: CISA: Adds Jenkins vulnerability to KEV List
No exploits have been reported in the wild yet, but the timing of the announcement aligns with the rise of CI/CD attacks. Organizations should review plugins, immediately apply SAML and MCP fixes, disable unused ones, and enable CSRF protections.
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