What is CVE-2026-66402?

CVE-2026-66402 is a critical-severity vulnerability in Freerdp, classified under Improper Certificate Validation. CVSS score: 9.8/10. Published 2026-08-01.

How severe is CVE-2026-66402?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Freerdp

CVE-2026-66402

FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains multiple TLS certificate identity validation weaknesses in tls_verify_certificate(), tls_match_hostname(), and x509_utils_get_dns_names(). Because FreeRDP performs custom Common…

Vulnerability class: Improper Certificate Validation

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Freerdp — versions 0, 3.29.0

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (patch)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-66402?: CVE-2026-66402 is a critical-severity vulnerability in Freerdp, classified under Improper Certificate Validation. CVSS score: 9.8/10. Published 2026-08-01.
How severe is CVE-2026-66402?: Critical severity. CVSS v3 base score is 9.8 out of 10.