GHSA-3244-j874-rhc2

Netty: Memory Exhaustion in RedisArrayAggregator due to Deeply Nested Arrays

At a glance

Published
Updated
CVE
CVE-2026-44250
CVSS_V3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Description

### Summary An attacker can cause DoS by sending a crafted Redis payload with deeply nested arrays. This forces the server to allocate a massive number of state objects and collections, leading to memory exhaustion and an OutOfMemoryError. ### Details io.netty.handler.codec.redis.RedisArrayAggregator aggregates RedisMessage parts into ArrayRedisMessage. It uses a `Deque<AggregateState>` to keep track of nested arrays. However, it does not limit the maximum depth of nested arrays. When an attacker sends a continuous stream of nested array headers (e.g., `*1\r\n*1\r\n*1\r\n...`), RedisArrayAggregator pushes a `new AggregateState` onto the stack and allocates a `new ArrayList` for each header. Because there is no depth limit, an attacker can send millions of such headers. This consumes a massive amount of heap memory for the AggregateState instances and their backing ArrayLists, eventually resulting in an OutOfMemoryError. ### Impact Denial of Service due to memory exhaustion. Any application using Netty's RedisArrayAggregator to handle untrusted Redis traffic is vulnerable.

Affected packages

PackageVersions
Maven · io.netty:netty-codec-redisintroduced 4.2.0.Final, fixed 4.2.15.Final
Maven · io.netty:netty-codec-redisintroduced 0, fixed 4.1.135.Final

References

Sources

SourceLicence
OSV.devCC-BY 4.0 — GitHub Advisory Database