Truncation of Security-relevant Information Affecting freerdp-devel package, versions <2:3.6.3-1.amzn2023.0.15


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.29% (21st percentile)

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  • Snyk IDSNYK-AMZN2023-FREERDPDEVEL-19476698
  • published1 Sept 2026
  • disclosed1 Aug 2026

Introduced: 1 Aug 2026

CVE-2026-66402  (opens in a new tab)
CWE-222  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 freerdp-devel to version 2:3.6.3-1.amzn2023.0.15 or higher.
This issue was patched in ALAS2023-2026-2111.

NVD Description

Note: Versions mentioned in the description apply only to the upstream freerdp-devel package and not the freerdp-devel package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1