CVE-2026-44890 Netty has Unbounded Direct Memory Consumption in its RedisDecoder
Attackers can cause denial of service in Netty Redis servers by exhausting direct memory with crafted payloads lacking line terminators.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44890?
CVE-2026-44890 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 crafted Redis payloads across multiple connections without `\r\n`. This exhausts the server's direct memory pool (OutOfDirectMemoryError), preventing legitimate connections from being processed. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Which versions are affected by CVE-2026-44890?
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-2026-44890?
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-2026-44890 being exploited?
There is no known exploitation of CVE-2026-44890 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-JW13513, CLEANSTART-2026-NS79946, CLEANSTART-2026-UB95848, CLSA-2026-1785291687, DEBIAN-CVE-2026-44890, GHSA-6ghj-frrj-jjj3 and 10 more.