Improper Certificate Validation Affecting freerdp/freerdp package, versions [,3.29.0)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UNMANAGED-FREERDPFREERDP-21192969
- published18 Oct 2026
- disclosed1 Aug 2026
- creditUnknown
Introduced: 1 Aug 2026
CVE-2026-66402 (opens in a new tab)How to fix?
Upgrade freerdp/freerdp to version 3.29.0 or higher.
Overview
Affected versions of this package are vulnerable to Improper Certificate Validation due to improper validation in the tls_verify_certificate, tls_match_hostname, and x509_utils_get_dns_names functions. An attacker can impersonate a trusted server by presenting a specially crafted certificate that exploits weaknesses in Common Name and DNS Subject Alternative Name string matching, such as truncation at embedded NUL bytes or acceptance of non-matching DNS SAN entries.