CVE-2026-54251
CVE-2026-54251 is a high-severity vulnerability with a CVSS 4.0 base score of 8.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-664.
Key facts
- Severity: High (CVSS 4.0 base score 8.7)
- EPSS exploit prediction: 1% (41st percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-664
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-54251?
- 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.
- How severe is CVE-2026-54251?
- CVE-2026-54251 has a CVSS 4.0 base score of 8.7, rated high severity.
- Is CVE-2026-54251 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-54251?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2026-54251 published?
- CVE-2026-54251 was published on 2026-09-15 and last updated on 2026-09-30.
References
- https://github.com/netty/netty-incubator-codec-ohttp/commit/ba6871bcbd6b3606872d2a81fabc73b284418bf8
- https://github.com/netty/netty-incubator-codec-ohttp/releases/tag/netty-incubator-codec-parent-ohttp-0.0.23.Final
- https://github.com/netty/netty-incubator-codec-ohttp/security/advisories/GHSA-vmr9-j6wf-pmh2
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