# 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.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Sep 2026
- **Updated:** 15 Sep 2026
- **Also known as:** GHSA-vmr9-j6wf-pmh2

## 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 (Improper Control of a Resource Through its Lifetime)

## 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 | Ecosystem | 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.

## Is CVE-2026-54251 being exploited?

There is no known exploitation of CVE-2026-54251 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-54251 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-54251 in the wild and no public exploit code.

Affected packages and fixed versions:
- io.netty.incubator:netty-incubator-codec-ohttp (Maven): affected all versions; fixed in 0.0.23.Final
- io.netty.incubator:netty-incubator-codec-ohttp (Maven): affected all versions; fixed in 0.0.23.Final

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-54251/ (Markdown: https://insights.sbomify.com/CVE-2026-54251/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54251
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54251
- OSV: https://osv.dev/vulnerability/CVE-2026-54251

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-54251/
Summaries are generated and may contain mistakes; the official description above is the record.