CVE-2026-29774 FreeRDP has a heap-buffer-overflow in avc420_yuv_to_rgb via OOB regionRects
A malicious RDP server can trigger a heap buffer overflow in the FreeRDP client, potentially allowing remote code execution or crashing the client.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-29774?
CVE-2026-29774 is a medium-severity memory corruption vulnerability in Freerdp Freerdp, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-787
Which versions are affected by CVE-2026-29774?
It affects 1 product.
Products include Freerdp Freerdp.
How do I fix CVE-2026-29774?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-29774 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-29774 exists.
Other vulnerabilities in Freerdp Freerdp
- CVE-2021-37594 Other in n/a
- CVE-2021-37595 Other in n/a
- CVE-2026-67305 FreeRDP Windows Client before 3.29.0 Heap Buffer Overflow via Cliprdr
- CVE-2026-66402 FreeRDP before 3.29.0 TLS Certificate Identity Validation Bypass
- CVE-2026-67289 FreeRDP before 3.29.0 HTTP Proxy Request Injection via Redirection
Sources
Also known as DEBIAN-CVE-2026-29774, GHSA-5q35-hv9x-7794, UBUNTU-CVE-2026-29774.