Name: CVE-2026-55194: Heap-based Buffer Overflow
Creator: Rapid7
Published: 2026-08-19T00:00:00.000Z
License: https://www.rapid7.com/legal/website-terms-of-use/
Keywords: CVE, CVE-2026-55194, CWE-122, CVSS 9.8, EPSS 0.00619

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, rpc_client_recv_fragment in libfreerdp/core/gateway/rpc_client.c ensures the response reassembly stream capacity using only the server-declared alloc_hint rather than the actual StubLength about to be written. A malicious TS Gateway can send a PTYPE_RESPONSE with a small alloc_hint and a much larger frag_length, causing Stream_Write to copy attacker-controlled stub data beyond the 4096-byte pdu->s buffer. This can crash the client and may permit code execution through heap corruption. This issue is fixed in version 3.27.0.

CVSS Details

CVSS 4.0 Base Score: 8.7 (HIGH)
CVSS 4.0 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X)
CVSS 3.1 Base Score: 9.8
CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Covered by Rapid7

Product	Vendor Advisory	Solution File	Added	Published
Alma_linux	—	Upgrade freerdpUpgrade libwinprUpgrade freerdp-develUpgrade libwinpr-develUpgrade freerdp-libs	Oct 11, 2026	Aug 31, 2026
Alpine Linux	—	Upgrade freerdp	Aug 20, 2026	Aug 19, 2026
Amazon Linux Ami 2	—	Upgrade freerdp-libsUpgrade libwinpr-develUpgrade freerdp-develUpgrade freerdp-debuginfoUpgrade libwinprUpgrade freerdp	Aug 5, 2026	Aug 5, 2026
Redhat_linux	—	Upgrade freerdp-develUpgrade freerdp-libsUpgrade libwinpr-debuginfoUpgrade freerdp-libs-debuginfoUpgrade freerdp-server-debuginfoUpgrade libwinprUpgrade freerdp-serverUpgrade libwinpr-develUpgrade freerdp-debuginfoUpgrade freerdp-debugsourceUpgrade freerdp	Aug 24, 2026	Aug 19, 2026
Rocky_linux	—	Upgrade freerdpUpgrade freerdp-debuginfoUpgrade freerdp-develUpgrade freerdp-server-debuginfoUpgrade libwinprUpgrade freerdp-serverUpgrade freerdp-libsUpgrade freerdp-debugsourceUpgrade libwinpr-debuginfoUpgrade freerdp-libs-debuginfoUpgrade libwinpr-devel	Sep 2, 2026	Sep 1, 2026
Ubuntu	—	Upgrade freerdp-x11Upgrade libfreerdp3-3Upgrade freerdp3-x11	Jul 21, 2026	Jul 20, 2026

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CVSS Details

Covered by Rapid7

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