Out-of-bounds Write Affecting libwinpr package, versions *


Severity

Recommended
0.0
medium
0
10

Based on CentOS security rating.

Threat Intelligence

EPSS
0.04% (13th percentile)

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  • Snyk IDSNYK-CENTOS9-LIBWINPR-15668812
  • published16 Mar 2026
  • disclosed13 Mar 2026

Introduced: 13 Mar 2026

NewCVE-2026-29774  (opens in a new tab)
CWE-787  (opens in a new tab)

How to fix?

There is no fixed version for Centos:9 libwinpr.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libwinpr package and not the libwinpr package as distributed by Centos. See How to fix? for Centos:9 relevant fixed versions and status.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, 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. In yuv.c, the clamp() function (line 347) only validates top/bottom against the surface/YUV height, but never checks left/right against the surface width. When avc420_yuv_to_rgb (line 67) computes destination and source pointers using rect->left, it performs unchecked pointer arithmetic that can reach far beyond the allocated surface buffer. A malicious server sends a WIRE_TO_SURFACE_PDU_1 with AVC420 codec containing a regionRects entry where left greatly exceeds the surface width (e.g., left=60000 on a 128px surface). The H.264 bitstream decodes successfully, then yuv420_process_work_callback calls avc420_yuv_to_rgb which computes pDstPoint = pDstData + rect->top * nDstStep + rect->left * 4, writing 16-byte SSE vectors 1888+ bytes past the allocated heap region. This vulnerability is fixed in 3.24.0.

CVSS Base Scores

version 3.1