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PatchSiren cyber security CVE debrief

CVE-2026-53436 Jenkins Project CVE debrief

CVE-2026-53436 is a medium-severity vulnerability in Jenkins that allows attackers to perform phishing attacks due to improper validation of redirect URLs after login. The vulnerability affects Jenkins 2.567 and earlier, as well as LTS 2.555.2 and earlier. The issue arises from the application's failure to properly determine if a redirect URL contains relative path segments (`./` or `../`), which can be exploited to redirect users to malicious sites.

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
2026-06-11
Advisory published
2026-06-10
Advisory updated
2026-06-11

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 the risk.

Technical summary

The vulnerability has a CVSS score of 4.3 and is classified as CWE-601. It allows attackers to perform phishing attacks by manipulating redirect URLs to point to malicious sites.

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-3711+3755)

Evidence notes

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

Sources and references

Verified primary and authoritative sources

  • CVE-2026-53436 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-53436

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-53436 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-53436

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.