Bug 2558750 (CVE-2026-110353)

Summary: CVE-2026-110353 haproxy: HAProxy: Denial of Service via truncated HTTP/2 PING frame
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: akhatavk, amctagga, aoconnor, aos-team-art-private, asdas, bniver, dpaolell, flucifre, gmeno, groman, jdelft, jupierce, lgarciaa, mbenjamin, mbiarnes, mhackett, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, sostapov, suppawar, vereddy, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in HAProxy. A remote, unauthenticated attacker can cause a Denial of Service (DoS) by sending a truncated HTTP/2 PING frame. Because the server fails to properly validate and process the incomplete frame, the pending data is never consumed, causing worker threads to spin continuously and exhaust CPU resources. This sustained resource exhaustion can degrade server performance or make the service unresponsive to legitimate users.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-22 03:01:29 UTC 
HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread CPU exhaustion) via a truncated HTTP/2 PING frame. h2c_handle_ping in src/mux_h2.c does not check for a short read, unlike the other H2 frame handlers. Because the incomplete frame cannot be processed, its data is never consumed, and the H2 multiplexer tasklet is repeatedly woken by that pending data without making progress. The CPU spins until timeout http-request closes the connection, and an attacker opening many such connections can sustain high CPU usage.