CVE-2026-8720
CVE-2026-8720 · HMAC-BLAKE2 final discards message when key length exceeds block size
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 5.9 · Medium · EPSS 0.2%
- Published
- Updated
Stack: system
Affected products and versions
wolfssl
- Versions
- ≥ 5.9.0, ≤ 5.9.1: Affected (semver)
No fix published
wolfssl Debian:12
- Versions
- 5.5.4-2
- 5.5.4-2+deb12u1
- 5.5.4-2+deb12u2
- 5.5.4-2+deb12u3
- 5.5.4-2.1
- 5.6.4-1
- 5.6.4-2
- 5.6.6-1
- 5.6.6-1.1
- 5.6.6-1.2
- 5.6.6-1.3
- 5.6.6-1.3~exp1
- 5.7.0-0.1
- 5.7.0-0.2
- 5.7.0-0.3
- 5.7.2-0.1
- 5.7.2-0.2
- 5.7.2-0.3
- 5.7.2-0.4
- 5.8.2-1
- 5.8.2-1.1
- 5.8.2-1.2
- 5.8.4-1
- 5.9.0-0.1
- 5.9.0-0.2
- 5.9.1-0.1
- 5.9.2-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Debian:13
- Versions
- 5.7.2-0.1
- 5.7.2-0.1+deb13u1
- 5.7.2-0.1+deb13u2
- 5.7.2-0.2
- 5.7.2-0.3
- 5.7.2-0.4
- 5.8.2-1
- 5.8.2-1.1
- 5.8.2-1.2
- 5.8.4-1
- 5.9.0-0.1
- 5.9.0-0.2
- 5.9.1-0.1
- 5.9.2-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:16.04:LTS
- Versions
- 3.4.8+dfsg-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:18.04:LTS
- Versions
- 3.10.2+dfsg-2
- 3.12.0+dfsg-1
- 3.12.2+dfsg-1
- 3.13.0+dfsg-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:20.04:LTS
- Versions
- 4.1.0+dfsg-2
- 4.2.0+dfsg-1
- 4.2.0+dfsg-2
- 4.2.0+dfsg-3
- 4.3.0+dfsg-2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:22.04:LTS
- Versions
- 4.6.0-3
- 5.0.0-1
- 5.1.1-1
- 5.2.0-1
- 5.2.0-2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:24.04:LTS
- Versions
- 5.5.4-2
- 5.5.4-2.1
- 5.6.4-2
- 5.6.6-1.2
- 5.6.6-1.3
- 5.6.6-1.3build1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:25.10
- Versions
- 5.7.2-0.1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:26.10
- Versions
- 5.9.1-0.1
- 5.9.2-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
wolfssl Ubuntu:26.04:LTS
- Versions
- 5.7.2-0.1
- 5.8.2-1.2
- 5.8.4-1
- 5.9.1-0.1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published