CVE-2026-55193

high

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP clients using TS Gateway accept a server-controlled max_xmit_frag value in libfreerdp/core/gateway/rpc_bind.c without bounding it to the 4088-byte ReceiveFragment allocation. A malicious gateway can advertise 65535 and then send a response fragment of the same length, causing rpc_channel_read in libfreerdp/core/gateway/rpc.c to write up to 65535 bytes into the smaller ReceiveFragment buffer. This can crash the client and may permit code execution through attacker-controlled heap corruption. This issue is fixed in version 3.27.0.

References

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-7rp4-66mc-j9vx

https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0

https://github.com/FreeRDP/FreeRDP/pull/12873

https://github.com/FreeRDP/FreeRDP/commit/a863ef1cf1cdabf9019280e5658f806e73bb50e8

Details

Source: Mitre, NVD

Published: 2026-08-19

Updated: 2026-08-27

Risk Information

CVSS v2

Base Score: 9

Vector: CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:P

Severity: High

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 8.7

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00626