Widely used Jenkins CI/CD; stored XSS could disrupt pipelines across many deployments.
CVE-2026-27099
Stored XSS in Jenkins UI via offline description input.
Is CVE-2026-27099 being exploited?
Not confirmed. CVE-2026-27099 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.46% probability of exploitation in the next 30 days.
How severe is CVE-2026-27099?
CVE-2026-27099 is rated High with a CVSS score of 8.0. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-27099?
Yes. A fix has been recorded for CVE-2026-27099. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-27099 affect?
CVE-2026-27099 affects Jenkins core 2.483-2.550, Jenkins LTS 2.492.1-2.541.1. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-27099?
Upgrade to patched Jenkins version immediately
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Stored XSS allows UI script execution, session hijack and UI tampering for users with Agent permissions.
Immediate action required