CVE-2026-44250 Netty: Memory Exhaustion in RedisArrayAggregator due to Deeply Nested Arrays
Attackers can cause denial of service in Netty Redis servers by sending deeply nested arrays, leading to memory exhaustion.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44250?
CVE-2026-44250 is a high-severity denial of service vulnerability in Netty Netty, published on 11 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Netty is a network application framework for development of protocol servers and clients. In netty-codec-redis prior to versions 4.1.135.Final and 4.2.15.Final, 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. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Which versions are affected by CVE-2026-44250?
4 open source packages ship an affected version, including io.netty:netty-codec-redis. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
io.netty:netty-codec-redis Maven | All versions | 4.1.135.Final |
io.netty:netty-codec-redis Maven | All versions | 4.1.135.Final |
io.netty:netty-codec-redis Maven | From 4.2.0.Final | 4.2.15.Final |
io.netty:netty-codec-redis Maven | From 4.2.0.Final | 4.2.15.Final |
Products include Netty Netty.
How do I fix CVE-2026-44250?
Upgrade io.netty:netty-codec-redis to a fixed version for your release line: 4.1.135.Final or 4.2.15.Final.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-44250 being exploited?
There is no known exploitation of CVE-2026-44250 in the wild and no public exploit code.
Other vulnerabilities in Netty Netty
- CVE-2026-75595 Netty: SNI Routing Bypass via Fragmented TLS ClientHello Causing Fallback to Default SslContext
- CVE-2026-75596 Netty: Fragmented ClientHello records trigger quadratic pre-handshake reassembly in default SNI parsing
- CVE-2026-59901 Netty Bzip2Decoder: Infinite Loop in RLE State Machine Leads to Event-Loop Thread Hang
- CVE-2026-55851 Netty codec-haproxy: Signed-Byte Sentinel Collision in HAProxyMessageDecoder Leads to Unbounded Memory Exhaustion
- CVE-2026-56745 Netty SpdyHttpDecoder: ByteBuf Reference Leak on RST_STREAM Leads to Native Memory Exhaustion
Sources
Also known as CLEANSTART-2026-CG75850, CLEANSTART-2026-GH03249, CLEANSTART-2026-WG67624, DEBIAN-CVE-2026-44250, GHSA-3244-j874-rhc2, MINI-4w89-7rf4-3pm6 and 9 more.