Jenkins 2.587 and earlier, LTS 2.580.1 and earlier checks for symbolic links in the path of an extracted file only before creating its parent director

Summary

Jenkins 2.587 and earlier, LTS 2.580.1 and earlier checks for symbolic links in the path of an extracted file only before creating its parent directories, not immediately before writing it, and allows symbolic links in artifacts to replace existing files or empty directories, allowing attackers with Item/Configure permission to write files to arbitrary locations on the Jenkins controller file system.

Remediation

1. Inventory every Jenkins Jenkins deployment, including staging.
2. Upgrade Jenkins Jenkins to the fixed version for your release line, listed under Affected versions.
3. Confirm the running version after the upgrade.

References

• Advisoryhttps://www.jenkins.io/security/advisory/2026-10-28/#SECURITY-4248