What is CVE-2026-5263?

CVE-2026-5263 is a medium-severity vulnerability in Wolfssl, classified under Improper Certificate Validation. CVSS score: 6.5/10. Published 2026-04-09.

How severe is CVE-2026-5263?

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

Vulnerability in Wolfssl

CVE-2026-5263

URI nameConstraints from constrained intermediate CAs are parsed but not enforced during certificate chain verification in wolfcrypt/src/asn.c. A compromised or malicious sub-CA could issue leaf certificates with URI SAN entries that viola…

Vulnerability class: Improper Certificate Validation

EPSS: 0.000 (6.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

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

Affected products

Wolfssl — versions 0

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

facts@wolfssl.com (Patch, Issue Tracking)

Frequently asked questions

What is CVE-2026-5263?: CVE-2026-5263 is a medium-severity vulnerability in Wolfssl, classified under Improper Certificate Validation. CVSS score: 6.5/10. Published 2026-04-09.
How severe is CVE-2026-5263?: Medium severity. CVSS v3 base score is 6.5 out of 10.