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
| Package | Versions |
|---|---|
| Maven · io.netty:netty-codec-redis | introduced 4.2.0.Final, fixed 4.2.15.Final |
| Maven · io.netty:netty-codec-redis | introduced 0, fixed 4.1.135.Final |
References
- https://github.com/netty/netty/security/advisories/GHSA-3244-j874-rhc2 WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-44250 ADVISORY
- https://github.com/netty/netty PACKAGE
- https://github.com/netty/netty/releases/tag/netty-4.1.135.Final WEB
- https://github.com/netty/netty/releases/tag/netty-4.2.15.Final WEB
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |