Bug 2542693 (CVE-2026-91095)

Summary: CVE-2026-91095 proxygen: proxygen: Denial of Service via use-after-free in WebTransport stream handling
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in proxygen. A remote attacker could cause a Denial of Service (DoS) or potentially execute arbitrary code by exploiting a use-after-free vulnerability. During WebTransport stream processing, internal handlers can return stream references that have already been deallocated and subsequently register them as active read callbacks. Accessing this freed memory can lead to memory corruption and cause the service to crash.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2542963    
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Description OSIDB Bzimport 2026-09-28 20:51:57 UTC 
In proxygen from v2024.10.28.00 until v2026.09.28.00, the HTTPTransaction::onWebTransportUniStream and HTTPTransaction::onWebTransportBidiStream APIs could return stream handles that the stream handler had already freed. HQSession then installed those handles as transport read callbacks, which could lead to use of freed memory.