CVE-2026-53436 is a medium-severity (CVSS 4.3) Open Redirect 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 Open Redirect via Relative Path Segments in Post-Login Redirect URL
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-2026-53436.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
org.jenkins-ci.main:jenkins-core☕org.jenkins-ci.main:jenkins-coreReal-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
Jenkins 2.567 and earlier, LTS 2.555.2 and earlier improperly determines that a redirect URL after login is legitimately pointing to Jenkins when it contains relative path segments (./ or ../), allowing attackers to perform phishing attacks.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.jenkins-ci.main:jenkins-core | ≥ 2.556&&< 2.568 | 2.568org.jenkins-ci.main:jenkins-core:2.568 |
| ☕Maven | org.jenkins-ci.main:jenkins-core | all versions | 2.555.3org.jenkins-ci.main:jenkins-core:2.555.3 |
Affected Products
jenkinsjenkinsDetection & mitigation playbook
Open-source dependencyDetect
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.
Fix
Update org.jenkins-ci.main:jenkins-core to 2.568 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-53436 is resolved across your whole dependency graph.
Workarounds
Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This Moderate impact flaw in Jenkins, as shipped in OpenShift Developer Tools & Services, allows attackers to conduct phishing attacks. By exploiting improper validation of redirect URLs containing relative path segments, an attacker can craft a malicious link that appears legitimate, deceiving users into revealing…
upgrade to Jenkins 2.568 or LTS 2.555.3Source: Red Hat security advisory for CVE-2026-53436 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-53436 in your dependencies?
Find it across Maven, including transitive dependencies.