CVE-2026-41207: Netty Netty-Incubator-Codec-Ohttp

Medium severity, CVSS 5.3. EPSS: 0.3% chance of exploitation in the next 30 days.

The netty incubator codec.bhttp is a java language binary http parser. Prior to version 0.0.21.Final, HKDF_expand returns non-NULL on failure. The byte[] is filled with zeros and has no way to distinguish success from failure. Since this output is used as HKDF key material for the response AEAD, a failure silently produces an all-zero key. When EVP_HPKE_CTX_export fails it also returns an empty byte[] array filled with zeros. This byte[] feeds directly into OHttpCrypto.createResponseAEAD(...). A silent all-zero export secret would produce a deterministic, attacker-predictable AEAD key. Version 0.0.21.Final patches the issue.

Affected products

• Netty Netty-Incubator-Codec-Ohttp: before 0.0.21 (fixed in 0.0.21)

Published 2026-06-04. Last modified 2026-07-22.