CVE-2026-56818

MEDIUM CVSS 3.1: 6.5 EPSS 0.46%
Updated Aug 08, 2026
Netty
Parameter Value
CVSS 6.5 (MEDIUM)
Type CWE-401 (Memory Leak), CWE-703
Vendor Netty
Public PoC No

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.136.Final and 4.2.16.Final, the RedisArrayAggregator Redis codec clears retained partial aggregate state when the maxNestedArrayDepth limit is exceeded, but it does not clear the same state when the sibling maxElements limit is exceeded. A peer can start a valid RESP array, send a bulk string child, then send a nested array header longer than the configured maxElements.

Netty throws a decoder exception in decodeRedisArrayHeader, but the existing partial aggregate remains retained in the handler. If the application leaves the channel alive after the exception, later messages are still consumed into the pre-error aggregate, allowing an unauthenticated peer to keep attacker-controlled aggregate state alive across a security-limit exception and pin retained pooled buffers. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

Attack Parameters

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

Impact Assessment

Confidentiality
None
No data leak
Integrity
Low
Partial data modification
Availability
Low
Partial disruption

CVSS Vector v3.1

Vulnerable Products

netty:netty