Out-of-bounds Read in Freerdp
CVE-2026-55192
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (36.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.001
Affected products
- Freerdp — versions < 3.27.0
Weakness classification (CWE)
References
- github.com/FreeRDP/FreeRDP/security/advisories/GHSA-3mmf-qh4f-frm6 (Exploit, Mitigation, Vendor Advisory)
- github.com/FreeRDP/FreeRDP/pull/12873 (Patch, Issue Tracking)
- github.com/FreeRDP/FreeRDP/commit/0cd45b70bb1fe6befd258ff64c46461947e99adb (Patch)
- github.com/FreeRDP/FreeRDP/releases/tag/3.27.0 (Release Notes)
Frequently asked questions
- What is CVE-2026-55192?
- CVE-2026-55192 is a high-severity vulnerability in Freerdp, classified under Out-of-bounds Read. CVSS score: 8.2/10. Published 2026-08-19.
- How severe is CVE-2026-55192?
- High severity. CVSS v3 base score is 8.2 out of 10.