CVE-2026-57303: Jenkins Assembla Plugin has an XXE vulnerability

June 24, 2026 (updated September 25, 2026)

Jenkins Assembla Plugin 1.4 and earlier does not configure its XML parser to prevent XML external entity (XXE) attacks when parsing responses from the configured Assembla server.

This allows attackers able to control the responses of the configured Assembla server to extract secrets from the Jenkins controller or perform server-side request forgery.

As of publication of this advisory, there is no fix.

References

github.com/advisories/GHSA-2q27-6p2h-q6r3
nvd.nist.gov/vuln/detail/CVE-2026-57303
www.jenkins.io/security/advisory/2026-06-24/

Code Behaviors & Features

Detect and mitigate CVE-2026-57303 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Learn more about Dependency Scanning →