CVE-2026-55191
FreeRDP is a free implementation of the Remote Desktop Protocol.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.60%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP clients that negotiate RDPGFX AVC444 with an H.264 decoder backend calculate the intermediate YUV444 allocation size in libfreerdp/codec/h264.c with 32-bit multiplication in avc444_ensure_buffer. A malicious RDP server can supply surface dimensions for which piDstStride multiplied by padDstHeight wraps to a small nonzero value, causing winpr_aligned_recalloc to allocate an undersized buffer before YUV420CombineToYUV444 writes using the actual stride and rectangle dimensions. This can cause a client crash and may permit code execution through attacker-influenced heap corruption. This issue is fixed in version 3.27.0.
- CVSS 4.0
- 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.60% probability · 47th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-122, CWE-190
- Source
- security-advisories@github.com
References
- https://github.com/FreeRDP/FreeRDP/commit/97f40b9e766af375f4e41ac6a3f4397d708d249c
- https://github.com/FreeRDP/FreeRDP/pull/12873
- https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vx73-w5q6-7jqr
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vx73-w5q6-7jqr
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.