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CVE-2026-53440 Jenkins Project CVE debrief

CVE-2026-53440 is a medium-severity vulnerability in Jenkins 2.567 and earlier, LTS 2.555.2 and earlier. The vulnerability occurs because the 'from' parameter in the 'Delegate to servlet container' security realm is not properly validated, allowing attackers to redirect users to an attacker-controlled domain after login, which can be used for phishing attacks.

Vendor
Jenkins Project
Product
Jenkins
CVSS
MEDIUM 4.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-10
Original CVE updated
2026-06-12
Advisory published
2026-06-10
Advisory updated
2026-06-12

Who should care

Administrators and users of Jenkins 2.567 and earlier, LTS 2.555.2 and earlier should be aware of this vulnerability and take necessary actions to mitigate it.

Technical summary

The vulnerability has a CVSS score of 4.3 and is classified as CWE-601. The affected versions of Jenkins are 2.567 and earlier, and LTS 2.555.2 and earlier. The vulnerability can be mitigated by updating to a fixed version of Jenkins.

Defensive priority

medium

Recommended defensive actions

  • Update Jenkins to version 2.568 or later, or LTS 2.555.3 or later.
  • Refer to the vendor advisory for more information: [ref-4](https://www.jenkins.io/security/advisory/2026-06-10/#SECURITY-3721)

Evidence notes

The information provided is based on the CVE record and the NVD detail page.

Official resources

CVE-2026-53440 was published on 2026-06-10T14:16:36.990Z and modified on 2026-06-12T01:03:40.350Z.