CVE-2026-31806

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.

References

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31806.json

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-rrqm-46rj-cmx2

https://github.com/FreeRDP/FreeRDP/commit/83d9aedea278a74af3e490ff5eeb889c016dbb2b

https://bugzilla.redhat.com/show_bug.cgi?id=2447376

https://access.redhat.com/security/cve/CVE-2026-31806

https://access.redhat.com/errata/RHSA-2026:9641

https://access.redhat.com/errata/RHSA-2026:9640

https://access.redhat.com/errata/RHSA-2026:6958

https://access.redhat.com/errata/RHSA-2026:6918

https://access.redhat.com/errata/RHSA-2026:6799

https://access.redhat.com/errata/RHSA-2026:6743

https://access.redhat.com/errata/RHSA-2026:6727

https://access.redhat.com/errata/RHSA-2026:6340

https://access.redhat.com/errata/RHSA-2026:19033

https://access.redhat.com/errata/RHSA-2026:11323

https://access.redhat.com/errata/RHSA-2026:10951

https://access.redhat.com/errata/RHSA-2026:10735

https://access.redhat.com/errata/RHSA-2026:10734

https://access.redhat.com/errata/RHSA-2026:10076

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4

EPSS