Bug 2536137 (CVE-2026-85718)

Summary: CVE-2026-85718 org.asynchttpclient/async-http-client: AsyncHttpClient: Denial of Service via TLS handshake failure
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: unspecifiedCC: gmalinko, janstey, pdelbell, rstepani
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in AsyncHttpClient. When configured with connection limits, the library can leak a connection permit if a Transport Layer Security (TLS) handshake fails before completion. This permit leak can lead to resource exhaustion, allowing a remote attacker to cause a denial of service by repeatedly failing TLS connection establishments, thereby preventing legitimate requests from being processed.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-17 16:09:13 UTC 
The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. From 3.0.8 until 3.0.12, a client with maxConnections or maxConnectionsPerHost set above zero leaks one connection permit whenever TLS connection establishment fails before the handshake completes. NettyConnectListener removes the partitionKeyLock permit from NettyResponseFuture before every failure path is bound to the channel closeFuture, so an abort can leave the permit unreleased. Repeated failures can permanently lock out one host under a per-host limit or drain the shared pool under a global limit, blocking later requests even when no connection remains open. The default unlimited connection setting is not affected. This issue is fixed in version 3.0.12.