Bug 2487545 (CVE-2026-53436)

Summary: CVE-2026-53436 jenkins: Jenkins: Phishing attacks via improper redirect URL validation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Jenkins. The system improperly validates redirect URLs after login, specifically when they contain relative path segments such as `./` or `../`. This vulnerability allows attackers to craft malicious URLs that appear legitimate, leading to successful phishing attacks against users.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-06-10 14:02:13 UTC
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 relative path segments (`./` or `../`), allowing attackers to perform phishing attacks.