What is CVE-2026-6091?

CVE-2026-6091 is a medium-severity vulnerability in Wolfssl, classified under Improper Certificate Validation. CVSS score: 6.5/10. Published 2026-06-25.

How severe is CVE-2026-6091?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Wolfssl

CVE-2026-6091

Partial-chain certificate verification may accept chains that terminate at a peer-supplied, untrusted intermediate certificate rather than a trusted anchor. An attacker could present a chain that ends at an intermediate they control and ha…

Vulnerability class: Improper Certificate Validation

EPSS: 0.001 (2.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.

Affected products

Wolfssl — versions 5.7.4

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-2026-6091?: CVE-2026-6091 is a medium-severity vulnerability in Wolfssl, classified under Improper Certificate Validation. CVSS score: 6.5/10. Published 2026-06-25.
How severe is CVE-2026-6091?: Medium severity. CVSS v3 base score is 6.5 out of 10.