Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Jenkins core (Maven org.jenkins-ci.main:jenkins-core) versions before 2.555.3, and from 2.556 up to 2.568, are affected. A redirect URL after login containing tab or newline characters between "//" is wrongly treated as pointing to Jenkins, so an attacker can send a user to an external site, enabling phishing. Upgrade to 2.555.3 for the LTS line or 2.568 for the weekly line.
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 0.0043, the 37th percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:16 UTC First seen by agentprime
- 31 Oct 2026, 14:16 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-463r-5m89-4xfr
- OSV: GHSA-463r-5m89-4xfr
- nvd.nist.gov/vuln/detail/CVE-2026-53437
- github.com/jenkinsci/jenkins/commit/b32f2f27a82ed187a34f55b05edcc4a83563d574
- github.com/jenkinsci/jenkins/commit/8ef52891b07eb639b38271e4bab5dab3c0f10fda
- www.jenkins.io/security/advisory/2026-06-10/#SECURITY-3711+3755
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53437.json
- github.com/jenkinsci/jenkins
- bugzilla.redhat.com/show_bug.cgi?id=2487544
- access.redhat.com/security/cve/CVE-2026-53437
- access.redhat.com/errata/RHSA-2026:60259
- access.redhat.com/errata/RHSA-2026:60256
- access.redhat.com/errata/RHSA-2026:60254
- access.redhat.com/errata/RHSA-2026:60252