CVE-2026-54251 netty-incubator-codec-ohttp: [OHttpServerCodec] Native Direct-Memory Leak on AEAD Decryption Failure Leads to Gateway Denial of Service
Attackers can cause native memory leaks in Netty OHTTP gateways by sending invalid encrypted requests, leading to service denial.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54251?
CVE-2026-54251 is a high-severity denial of service vulnerability in io.netty.incubator netty-incubator-codec-ohttp, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
netty-incubator-codec-ohttp implements Oblivious HTTP (OHTTP) gateway and client functionality using Netty. Prior to 0.0.23.Final, the OHTTP gateway decryption path in codec-ohttp/src/main/java/io/netty/incubator/codec/ohttp/OHttpRequestResponseContext.java allocates a pooled direct ByteBuf for decrypted plaintext before the AEAD tag is verified. When an invalid tag causes decryptChunk() to throw CryptoException, OHttpRequestResponseContext.decodeChunk() does not release the ByteBuf because the allocation is not guarded by try/finally. Repeated invalid encrypted requests can therefore leak native off-heap memory until the gateway is unable to continue serving requests. This issue is fixed in version 0.0.23.Final.
Weakness: CWE-664
Which versions are affected by CVE-2026-54251?
2 open source packages ship an affected version, including io.netty.incubator:netty-incubator-codec-ohttp.
| Package | Affected | Fixed in |
|---|---|---|
io.netty.incubator:netty-incubator-codec-ohttp Maven | All versions | 0.0.23.Final |
io.netty.incubator:netty-incubator-codec-ohttp Maven | All versions | 0.0.23.Final |
How do I fix CVE-2026-54251?
Upgrade io.netty.incubator:netty-incubator-codec-ohttp to 0.0.23.Final or later.
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-2026-54251 being exploited?
There is no known exploitation of CVE-2026-54251 in the wild and no public exploit code.
Sources
Also known as GHSA-vmr9-j6wf-pmh2.