Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Jenkins core (org.jenkins-ci.main:jenkins-core) versions from 2.556 before 2.568, and versions before 2.555.3, are affected. Jenkins improperly treats a post-login redirect URL containing relative path segments as pointing to Jenkins, so an attacker can craft a link that sends users to an external site after login, enabling phishing. Upgrade to 2.568 or 2.555.3, or to a later fixed release.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 4.3 | Medium | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N | GitHub Advisory Database |
- CISA KEV Not listed.
- EPSS 0.0026, the 17th percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:17 UTC First seen by agentprime
- 31 Oct 2026, 14:17 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-3rqh-hch3-jhpc
- OSV: GHSA-3rqh-hch3-jhpc
- nvd.nist.gov/vuln/detail/CVE-2026-53436
- github.com/jenkinsci/jenkins/commit/8ef52891b07eb639b38271e4bab5dab3c0f10fda
- github.com/jenkinsci/jenkins/commit/b32f2f27a82ed187a34f55b05edcc4a83563d574
- github.com/jenkinsci/jenkins
- www.jenkins.io/security/advisory/2026-06-10/#SECURITY-3711+3755