CVE-2026-8720 Affecting wolfssl package, versions <5.9.2-1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.11% (2nd percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-WOLFSSL-17547488
  • published26 Jun 2026
  • disclosed25 Jun 2026

Introduced: 25 Jun 2026

NewCVE-2026-8720  (opens in a new tab)

How to fix?

Upgrade Debian:unstable wolfssl to version 5.9.2-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream wolfssl package and not the wolfssl package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

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.