What is CVE-2026-27099?

CVE-2026-27099 is a high-severity vulnerability in Jenkins, classified under Cross-site Scripting. CVSS score: 8.0/10. Published 2026-02-18.

How severe is CVE-2026-27099?

High severity. CVSS v3 base score is 8.0 out of 10.

XSS in Jenkins

CVE-2026-27099

Jenkins 2.483 through 2.550 (both inclusive), LTS 2.492.1 through 2.541.1 (both inclusive) does not escape the user-provided description of the "Mark temporarily offline" offline cause, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers with Agent/Configure or Agent/Disconnect permission.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.005 (37.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.0 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H.

Affected products

Jenkins
Jenkins Project — versions 0, 2.551, 2.541.2

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

jenkinsci-cert@googlegroups.com (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-27099?: CVE-2026-27099 is a high-severity vulnerability in Jenkins, classified under Cross-site Scripting. CVSS score: 8.0/10. Published 2026-02-18.
How severe is CVE-2026-27099?: High severity. CVSS v3 base score is 8.0 out of 10.