CVE-2026-85718

MEDIUM CVSS 3.1: 5.9 EPSS 0.53%
Updated Sep 30, 2026
Java
Parameter Value
CVSS 5.9 (MEDIUM)
Fixed In 3.0.12
Type CWE-400 (Uncontrolled Resource Consumption), CWE-772
Vendor Java
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service

CVSS Vector v3.1