Vulnerability · Published Aug 1, 2026 · Assigned by VulnCheck
CVE-2026-67298FreeRDP 3.28.0 Heap Buffer Overflow via RAIL orderLength Underflow
High 7.5
In plain English
A high-severity security flaw in FreeRDP from FreeRDP. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | freerdp | 2:3.10.3-12.el10_2.10 | ALSA-2026:61378 |
| AlmaLinux:10 | freerdp-devel | 2:3.10.3-12.el10_2.10 | ALSA-2026:61378 |
| AlmaLinux:10 | freerdp-libs | 2:3.10.3-12.el10_2.10 | ALSA-2026:61378 |
| AlmaLinux:10 | freerdp-server | 2:3.10.3-12.el10_2.10 | ALSA-2026:61378 |
| AlmaLinux:10 | libwinpr | 2:3.10.3-12.el10_2.10 | ALSA-2026:61378 |
| AlmaLinux:10 | libwinpr-devel | 2:3.10.3-12.el10_2.10 | ALSA-2026:61378 |
| Debian:12 | freerdp2 | no fix listed | DEBIAN-CVE-2026-67298 |
| Debian:13 | freerdp3 | no fix listed | DEBIAN-CVE-2026-67298 |
| Debian:14 | freerdp3 | 3.29.0+dfsg-1 | DEBIAN-CVE-2026-67298 |
| Rocky Linux:10 | freerdp | 2:3.10.3-12.el10_2.10 | RLSA-2026:61378 |
| Ubuntu:22.04:LTS | freerdp2 | no fix listed | UBUNTU-CVE-2026-67298 |
| Ubuntu:24.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.24.04.1 | UBUNTU-CVE-2026-67298 |
| Ubuntu:26.04:LTS | freerdp3 | 3.30.0+dfsg-0ubuntu0.26.04.1 | UBUNTU-CVE-2026-67298 |
Affected products (as reported)
Weakness: CWE-191 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H