CVE-2026-53437

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-10 · updated 2026-10-26
Weakness: CWE-601

Description

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 tab or newline characters between `//`, allowing attackers to perform phishing attacks.

Affected products

Jenkins: before 2.555.3; before 2.568 — fixed in 2.555.3, 2.568

How to fix

Upgrade to a fixed version: Jenkins 2.555.3, 2.568. Check the vendor advisory for mitigations.

References

https://www.jenkins.io/security/advisory/2026-06-10/#SECURITY-3711+3755
https://access.redhat.com/errata/RHSA-2026:60239
https://access.redhat.com/errata/RHSA-2026:60246
https://access.redhat.com/errata/RHSA-2026:60247
https://access.redhat.com/errata/RHSA-2026:60248
https://access.redhat.com/errata/RHSA-2026:60249
https://access.redhat.com/errata/RHSA-2026:60250
https://access.redhat.com/errata/RHSA-2026:60251
https://access.redhat.com/errata/RHSA-2026:60252
https://access.redhat.com/errata/RHSA-2026:60254
https://access.redhat.com/errata/RHSA-2026:60256
https://access.redhat.com/errata/RHSA-2026:60259

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