CVE-2026-67298
FreeRDP versions 3.28.0 and earlier contain a heap buffer overflow in the server-side RAIL channel handler (rail_server_handle_messages() in channels/rail/server/rail_main.c).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
FreeRDP versions 3.28.0 and earlier contain a heap buffer overflow in the server-side RAIL channel handler (rail_server_handle_messages() in channels/rail/server/rail_main.c). When processing a RAIL PDU header, the code subtracts RAIL_PDU_HEADER_LENGTH from the peer-controlled orderLength field without first verifying orderLength is at least the header length. For orderLength values 0..3 this causes an unsigned integer underflow to a very large size, which bypasses the Stream_EnsureRemainingCapacity() capacity check (due to pointer arithmetic wraparound) and is then passed to WTSVirtualChannelRead(), resulting in an out-of-bounds heap write. A malicious or compromised RDP client can exploit this to corrupt the heap and crash the server. Fixed in FreeRDP 3.29.0.
- CVSS 4.0
- 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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
- 0.38% probability · 31th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-191
- Source
- disclosure@vulncheck.com
References
- https://github.com/FreeRDP/FreeRDP/commit/46848765f2a1134f8652f8760eefb5e85d64a9b8
- https://github.com/FreeRDP/FreeRDP/commit/5370fb26fbf034ecd11d3026b6ad639b5fff493f
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qmvw-52ph-q5pv
- https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-via-rail-orderlength-underflow
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-5wr6-8m8j-3h7f
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.