Vulnerability in Netty Netty-Incubator-Codec-Ohttp

CVE-2026-41207

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.

EPSS: 0.002 (9.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-41207?
CVE-2026-41207 is a medium-severity vulnerability in Netty Netty-Incubator-Codec-Ohttp, classified under Use of Insufficiently Random Values. CVSS score: 5.3/10. Published 2026-06-04.
How severe is CVE-2026-41207?
Medium severity. CVSS v3 base score is 5.3 out of 10.