cvedb.io
CVE-2026-66402
CRITICAL · CVSS 9.8
EPSS exploitation probability: 0%
Published 2026-08-01T13:16:57.487 · Last modified 2026-08-01T13:16:57.487

Summary

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 Name and DNS SAN string matching instead of using OpenSSL's length-aware identity validation APIs, it (1) truncates DNS SAN values at embedded NUL bytes (accepting e.g. 'victim.example\0.attacker.example' as 'victim.example'), (2) accepts a matching Common Name even when non-matching DNS SAN entries are present, and (3) accepts IP-literal targets via DNS/CN matching without comparing iPAddress SANs. Under a trusted or misissued certificate chain, an attacker positioned to present such a certificate can bypass server identity verification, weakening TLS se

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.