VULNERABILITY INTELLIGENCE

CVE-2026-8720

CVSS score7.5 HIGH
EPSS probability0.16%
CISA KEVNot currently listed
Published2026-06-25
Last modified2026-06-27
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Description

wc_Blake2bHmacFinal and wc_Blake2sHmacFinal discard the message when the key length exceeds the block size, producing a MAC that is independent of the input. When the supplied key is longer than the BLAKE2 block size the key-hashing branch reinitialized the running hash state, discarding the accumulated message data, so the resulting MAC depended only on the key and not on the message being authenticated. This bug is specific to the HMAC-BLAKE2 APIs that were added in wolfSSL version 5.9.0.

Weakness classification

  • facts@wolfssl.com: CWE-354

Primary references