Vulnerability · Published Aug 19, 2026 · Assigned by GitHub_M
CVE-2026-55192FreeRDP: Out-of-bounds read in H.264 YUV-to-RGB conversion due to decoder/surface dimension mismatch
High 7.2
In plain English
A high-severity out-of-bounds read in FreeRDP from FreeRDP. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP H.264 decoder backends can return YUV planes sized from the bitstream without comparing the decoded width and height to the RDPGFX surface dimensions used to validate region rectangles. A malicious RDP server can provide an AVC420 or AVC444 bitstream whose decoded frame is smaller than the negotiated surface, causing yuv420_context_decode and the YUV-to-RGB conversion paths to read beyond the decoder-owned planes in libfreerdp/codec/h264.c and the selected H.264 backend. This can disclose client memory or crash the client. This issue is fixed in version 3.27.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.24 | freerdp | 3.27.1-r0 | ALPINE-CVE-2026-55192 |
| Debian:12 | freerdp2 | no fix listed | DEBIAN-CVE-2026-55192 |
| Debian:13 | freerdp3 | no fix listed | DEBIAN-CVE-2026-55192 |
| Debian:14 | freerdp3 | 3.27.0+dfsg-1 | DEBIAN-CVE-2026-55192 |
| Ubuntu:22.04:LTS | freerdp2 | no fix listed | UBUNTU-CVE-2026-55192 |
| Ubuntu:24.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.24.04.1 | USN-8561-1 |
| Ubuntu:24.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.24.04.1 | UBUNTU-CVE-2026-55192 |
| Ubuntu:25.10 | freerdp3 | no fix listed | UBUNTU-CVE-2026-55192 |
| Ubuntu:26.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.26.04.1 | USN-8561-1 |
| Ubuntu:26.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.26.04.1 | UBUNTU-CVE-2026-55192 |
Affected products (as reported)
Weakness: CWE-125 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N
References
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-3mmf-qh4f-frm6 x_refsource_CONFIRM
- https://github.com/FreeRDP/FreeRDP/pull/12873 x_refsource_MISC
- https://github.com/FreeRDP/FreeRDP/commit/0cd45b70bb1fe6befd258ff64c46461947e99adb x_refsource_MISC
- https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0 x_refsource_MISC