Memory leak in Netty - CVE-2026-56818
Published: August 5, 2026
Vulnerability identifier: #VU140941
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-56818
CWE-ID: CWE-401
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to retain partial aggregate state and cause integrity and availability impacts.
The vulnerability exists due to improper handling of exceptional conditions in RedisArrayAggregator when processing a RESP array header that exceeds the configured maxElements limit. A remote attacker can send a specially crafted Redis message sequence to retain partial aggregate state and cause integrity and availability impacts.
Exploitation requires the application to keep the channel alive after the decoder exception so that later messages are consumed into the stale aggregate state.
Affected software
Netty
How to mitigate CVE-2026-56818
Install security update from vendor's website.
Netty - addressed in versions 4.1.136, 4.2.16