What is CVE-2026-8720?

CVE-2026-8720 is a high-severity vulnerability in Wolfssl, classified under Improper Validation of Integrity Check Value. CVSS score: 7.5/10. Published 2026-06-25.

How severe is CVE-2026-8720?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Wolfssl

CVE-2026-8720

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…

EPSS: 0.001 (1.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

Wolfssl — versions 5.9.0

Weakness classification (CWE)

CWE-354 — Improper Validation of Integrity Check Value

References

facts@wolfssl.com (Patch, patch, Issue Tracking)
facts@wolfssl.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-8720?: CVE-2026-8720 is a high-severity vulnerability in Wolfssl, classified under Improper Validation of Integrity Check Value. CVSS score: 7.5/10. Published 2026-06-25.
How severe is CVE-2026-8720?: High severity. CVSS v3 base score is 7.5 out of 10.