CVE-2026-29774

NameCVE-2026-29774
DescriptionFreeRDP 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.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
freerdp2 (PTS)bullseye2.3.0+dfsg1-2+deb11u1vulnerable
bullseye (security)2.3.0+dfsg1-2+deb11u3vulnerable
bookworm2.11.7+dfsg1-6~deb12u1vulnerable
freerdp3 (PTS)trixie3.15.0+dfsg-2.1vulnerable
forky3.23.0+dfsg-1vulnerable
sid3.24.0+dfsg-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
freerdp2source(unstable)(unfixed)
freerdp3source(unstable)3.24.0+dfsg-1

Notes

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-5q35-hv9x-7794
Fixed by: https://github.com/FreeRDP/FreeRDP/commit/6482b7a92fff3959582cef052d1967ad6bde3738 (3.24.0)

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