Bug 2548703 (CVE-2026-61642)

Summary: CVE-2026-61642 squid: squid: Request Smuggling in HTTP Transfer-Encoding
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: gbenhaim, niyer, rhel-process-autobot, twaugh, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Squid. Due to improper handling of HTTP/1.1 Transfer-Encoding headers, a trusted client can perform an HTTP request smuggling attack, interfering with how web requests are processed. This vulnerability allows an attacker to bypass intermediate security controls. When an HTTP cache operates in front of the affected Squid instance, the attacker can also poison that cache, causing it to store and deliver malicious content to other users.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On: 2548716    
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Description OSIDB Bzimport 2026-10-09 15:53:38 UTC
A request smuggling vulnerability was found in Squid. Due to improper enforcement of behavioral workflow when processing HTTP/1.1 Transfer-Encoding headers, a trusted client can perform an HTTP request smuggling attack. This can bypass security mechanisms between the attacker and Squid. When an HTTP cache operates prior to the affected Squid instance, this also allows cache poisoning, enabling the attacker to store arbitrary malicious content at any URL for delivery to other clients.

Squid versions 3.3.0.1 through 7.5 are affected. The fix is available in version 7.6.