What is CVE-2026-53440?

CVE-2026-53440 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-2026-53440?

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

Open Redirect in Jenkins

CVE-2026-53440

Jenkins 2.567 and earlier, LTS 2.555.2 and earlier does not ensure that the "from" parameter in the "Delegate to servlet container" security realm is safe to redirect to after login, allowing attackers to perform phishing attacks by redire…

Vulnerability class: Open Redirect

EPSS: 0.002 (15.1th percentile) — read the EPSS interpretation.

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.

Affected products

Jenkins
Jenkins Project — versions 2.568, 2.555.3

Weakness classification (CWE)

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

References

jenkinsci-cert@googlegroups.com (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-53440?: CVE-2026-53440 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-2026-53440?: Medium severity. CVSS v3 base score is 4.3 out of 10.