CVE-2026-29774

A heap based buffer overflow flaw has been discovered in FreeRDP. A client-side heap buffer overflow occurs in the FreeRDP client's AVC420/AVC444 YUV-to-RGB conversion path due to missing horizontal bounds validation of H.264 metablock regionRects coordinates. A malicious server can trigger a client-side heap buffer overflow (WRITE of 16 bytes via SSE), causing a crash (DoS) and heap corruption. The attacker controls the offset via the left coordinate, potentially enabling arbitrary write to adjacent heap objects with code-execution risk depending on allocator layout.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.