Netty-codec-redis versions prior to 4.1.135.Final and 4.2.15.Final contain a vulnerability where an attacker can cause a denial of service (DoS) by sending a crafted Redis payload with deeply nested arrays. This leads to excessive memory allocation and an OutOfMemoryError, disrupting service availability. The issue is patched in versions 4.1.135.Final and 4.2.15.Final.