What is CVE-2026-6731?

CVE-2026-6731 is a high-severity vulnerability in Wolfssl, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2026-06-25.

How severe is CVE-2026-6731?

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

Vulnerability in Wolfssl

CVE-2026-6731

X.509 name constraint bypass via the Subject Common Name when treated as a DNS-type name. A certificate whose Subject CN violates an issuing CA's DNS name constraints could be accepted.

Vulnerability class: Improper Certificate Validation

EPSS: 0.001 (2.5th 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 3.9.10

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

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

Frequently asked questions

What is CVE-2026-6731?: CVE-2026-6731 is a high-severity vulnerability in Wolfssl, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2026-06-25.
How severe is CVE-2026-6731?: High severity. CVSS v3 base score is 7.5 out of 10.