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)

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.006 (44.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 44.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-27099: held from 0.005 to 0.006.

EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.001

Affected products

Weakness classification (CWE)

References

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.