Freerdp · Freerdp · CVE-2026-66402
**Name of the Vulnerable Software and Affected Versions**
FreeRDP versions prior to 3.29.0
**Description**
Weaknesses in TLS certificate identity validation occur within the `tls verify certificate()`, `tls match hostname()`, and `x509 utils get dns names()` functions. The software uses custom Common Name and DNS SAN string matching instead of OpenSSL's length-aware identity validation APIs. This leads to three issues: DNS SAN values are truncated at embedded NUL bytes, a matching Common Name is accepted even if non-matching DNS SAN entries exist, and IP-literal targets are accepted via DNS/CN matching without comparing iPAddress SANs. An attacker with a trusted or misissued certificate chain can bypass server identity verification, compromising TLS server authentication.
**Recommendations**
Update to version 3.29.0 or later.