Bug 2452408 (CVE-2026-34475)

Summary: CVE-2026-34475 Varnish Cache: Varnish Cache and Varnish Enterprise: Cache poisoning and authentication bypass via unchecked URL handling
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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 Varnish Cache and Varnish Enterprise. A remote attacker could exploit this vulnerability by sending specially crafted HTTP/1.1 requests with a path of `/` in the URL. This mishandling of URLs, specifically in unchecked `req.url` scenarios, could lead to cache poisoning, where an attacker manipulates cached content, or an authentication bypass, allowing unauthorized access.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-03-27 20:01:55 UTC
Varnish Cache before 8.0.1 and Varnish Enterprise before 6.0.16r12, in certain unchecked req.url scenarios, mishandle URLs with a path of / for HTTP/1.1, potentially leading to cache poisoning or authentication bypass.