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CVE PROGRAM SOURCE RECORD9.3 Critical

CVE-2026-66402

FreeRDP before 3.29.0 TLS Certificate Identity Validation Bypass

Description

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 server authentication.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

FreeRDP FreeRDP

Default version status: unaffected

  • 0 to < 3.29.0affected
  • 3.29.0unaffected

References