Vulnerability Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, the gdi_surface_bits() function processes SURFACE_BITS_COMMAND messages sent by the RDP server. When the command is handled using NSCodec, the bmp.width and bmp.height values provided by the server are not properly validated against the actual desktop dimensions. A malicious RDP server can supply crafted bmp.width and bmp.height values that exceed the expected surface size. Because these values are used during bitmap decoding and memory operations without proper bounds checking, this can lead to a heap buffer overflow. Since the attacker can also control the associated pixel data transmitted by the server, the overflow may be exploitable to overwrite adjacent heap memory. This vulnerability is fixed in 3.24.0.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Freerdp | Freerdp | < 3.24.0 |
Related Weaknesses (CWE)
References
- https://github.com/FreeRDP/FreeRDP/commit/83d9aedea278a74af3e490ff5eeb889c016dbbPatch
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-rrqm-46rj-cmx2ExploitPatchVendor Advisory
FAQ
What is CVE-2026-31806?
CVE-2026-31806 is a vulnerability with a CVSS score of 9.8 (CRITICAL). FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, the gdi_surface_bits() function processes SURFACE_BITS_COMMAND messages sent by the RDP server. When the command is h...
How severe is CVE-2026-31806?
CVE-2026-31806 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-31806?
Check the references section above for vendor advisories and patch information. Affected products include: Freerdp Freerdp.