Auth bypass in Jenkins

CVE-2026-84657

In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, the build CLI command does not check the Item/Cancel permission when using the -s flag to cancel a build triggered to wait for completion, allowing attackers with Item/Build permission to cancel builds started by other users.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L.

EPSS exploit prediction

EPSS: 0.003 (15.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 15.7% 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-2026-84657: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-84657?
CVE-2026-84657 is a medium-severity vulnerability in Jenkins, classified under Missing Authorization. CVSS score: 4.2/10. Published 2026-09-02.
How severe is CVE-2026-84657?
Medium severity. CVSS v3 base score is 4.2 out of 10.