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MEDIUM severity

CVE-2026-53438 — jenkins-core

MEDIUMFix: jenkinsci/jenkins@a154e11

CVE-2026-53438 is a medium-severity (CVSS 4.3) CWE-862 vulnerability in org.jenkins-ci.main:jenkins-core. A fix is available for org.jenkins-ci.main:jenkins-core — see the affected versions and patch details below.

Jenkins: Missing permission check allows unauthorized cancellation of queue items

Also known asBIT-jenkins-2026-53438GHSA-mw82-xcg6-gx79
Published
Jun 10, 2026
Updated
Aug 13, 2026
Affected
2 pkgs
Patched
2 / 2
Exploits
None indexed
Exploitation data as of Sep 27, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-53438.

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs18th percentile — riskier than 18% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-53438 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 380,066 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

2 pkgs affected
☕org.jenkins-ci.main:jenkins-core☕org.jenkins-ci.main:jenkins-core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

A missing permission check in Jenkins 2.567 and earlier, LTS 2.555.2 and earlier allows attackers with Item/Cancel permission, but lacking Item/Read permission, to cancel queue items they do not have permission to view.

Affected Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
☕Mavenorg.jenkins-ci.main:jenkins-coreall versions2.555.3org.jenkins-ci.main:jenkins-core:2.555.3
☕Mavenorg.jenkins-ci.main:jenkins-core≥ 2.556&&< 2.5682.568org.jenkins-ci.main:jenkins-core:2.568

Affected Products

1 product · 2 configurations
Application
jenkinsjenkins
< 2.568
range

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.jenkins-ci.main:jenkins-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update org.jenkins-ci.main:jenkins-core to 2.555.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-53438 is resolved across your whole dependency graph.

  3. Workarounds

    Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

A missing permission check in Jenkins 2.567 and earlier, LTS 2.555.2 and earlier allows attackers with Item/Cancel permission, but lacking Item/Read permission, to cancel queue items they do not have permission to view.
O3 Security · Impact-Aware SCA

Is CVE-2026-53438 in your dependencies?

Find it across Maven, including transitive dependencies.

CVE-2026-53438: jenkins-core (Medium 4.3) | O3 Security