CVE-2026-50011 Netty has unbounded pre-allocation in RedisArrayAggregator from RESP array length
Attackers can cause denial of service in Netty by sending malicious Redis array headers that trigger excessive memory pre-allocation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-50011?
CVE-2026-50011 is a high-severity denial of service vulnerability in Netty Netty, published on 12 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. Prior to versions 4.1.135.Final and 4.2.15.Final, RedisArrayAggregator pre-allocates ArrayList with initial capacity equal to the RESP array element count declared in an array header. That count is taken from the wire before the corresponding child messages exist. A small malicious header can claim a huge initial capacity. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Which versions are affected by CVE-2026-50011?
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-2026-50011?
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-2026-50011 being exploited?
There is no known exploitation of CVE-2026-50011 in the wild and no public exploit code.
Public exploit code: 2 proofs of concept on GitHub.
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-FA82841, CLEANSTART-2026-QJ97143, CLEANSTART-2026-YA82976, DEBIAN-CVE-2026-50011, GHSA-5w86-c3rq-vjj7, MINI-688p-9r3c-384g and 9 more.