CVE-2026-56818
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk38th percentile - higher than 38% of all known CVEs
Summary
In Netty before versions 4.1.136.Final and 4.2.16.Final, the RedisArrayAggregator codec does not clear partial aggregate state after exceeding the maxElements limit, allowing an unauthenticated peer to keep aggregate state alive after an exception and pin retained pooled buffers.
Risk Assessment
The attack can lead to memory leaks or application crashes, and may allow a remote attacker to manipulate connection state.
Recommendation
Upgrade Netty to version 4.1.136.Final or 4.2.16.Final, which include the fix.
Original NVD description (English source)
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.