What is CVE-2026-53436?

CVE-2026-53436 is a medium-severity vulnerability in Jenkins, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 4.3/10. Published 2026-06-10.

How severe is CVE-2026-53436?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Open Redirect in Jenkins

CVE-2026-53436

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.

Vulnerability class: Open Redirect

Published 2026-06-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (27.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Jenkins
Jenkins Project — versions 2.568, 2.555.3

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

References

www.jenkins.io/security/advisory/2026-06-10/ (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-53436?: CVE-2026-53436 is a medium-severity vulnerability in Jenkins, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 4.3/10. Published 2026-06-10.
How severe is CVE-2026-53436?: Medium severity. CVSS v3 base score is 4.3 out of 10.