CVE-2026-53437: Jenkins 2.567 and earlier, LTS 2.555.2 and earlier improperly determines that a redirect URL after login is le

Q: How do I fix CVE-2026-53437?

jenkins: upgrade to 2.555.3, 2.568. Exact commands for each OS are on this page.

Q: Is CVE-2026-53437 being exploited?

CVE-2026-53437 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-53437 affect?

CVE-2026-53437 affects jenkins. Severity is medium (CVSS 4.3). 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 att

Q: How urgent is CVE-2026-53437?

Priority 25/100. No elevated risk signals yet.

Routine

MEDIUM 4.3UPGRADE

CVE-2026-53437 is a medium-severity flaw (CVSS 4.3) affecting jenkins. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.5% (top 60%)
CISA exploited list	No
Weakness	CWE-601
Published	2026-06-10
Last modified	2026-10-26

Publisher (CNA): Jenkins Project · Vendor: jenkins

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-10 14:16 UTCPublished CVE record published
2026-10-26 11:10 UTCUpdated Record last modified

jenkins jenkins UPGRADE

Affected: < 2.555.3 · < 2.568

Fixed in: 2.555.3, 2.568

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy jenkins || rpm -q jenkins || jenkins --version

2. UPGRADE to 2.555.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade jenkins

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade jenkins

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-53437?

jenkins: upgrade to 2.555.3, 2.568. Exact commands for each OS are on this page.

Is CVE-2026-53437 being exploited?

CVE-2026-53437 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-53437 affect?

CVE-2026-53437 affects jenkins. Severity is medium (CVSS 4.3). 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 att

How urgent is CVE-2026-53437?

Priority 25/100. No elevated risk signals yet.

Software pages

Jenkins vulnerabilities

Related CVEs

CVE-2026-53435 HIGH 8.8 UPGRADE In Jenkins 2.567 and earlier, LTS 2.555.2 and earlier, it is possible for attackers to have Jenkins deserializ
CVE-2026-53442 MEDIUM 5.3 UPGRADE Jenkins 2.567 and earlier, LTS 2.555.2 and earlier does not encrypt secrets from POST config.xml submissions b
CVE-2026-53441 MEDIUM 5.4 UPGRADE Jenkins 2.483 through 2.567 (both inclusive), LTS 2.492.1 through 2.555.2 (both inclusive) does not escape the
CVE-2026-53436 MEDIUM 4.3 UPGRADE Jenkins 2.567 and earlier, LTS 2.555.2 and earlier improperly determines that a redirect URL after login is le
CVE-2026-53438 MEDIUM 4.3 UPGRADE A missing permission check in Jenkins 2.567 and earlier, LTS 2.555.2 and earlier allows attackers with Item/Ca

References

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