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Vulnerability · Published Aug 19, 2026 · Assigned by GitHub_M

CVE-2026-55193FreeRDP: Heap-buffer-overflow write in TS Gateway RPC fragment receive due to uncapped bind_ack max_xmit_frag

High 8.7

In plain English

A high-severity heap buffer overflow in FreeRDP from FreeRDP. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.7High
Exploit odds (30 days)0.5%top 58.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:10freerdp2:3.10.3-12.el10_2.11ALSA-2026:66349
AlmaLinux:8freerdp2:2.11.7-13.el8_10ALSA-2026:69387
AlmaLinux:9freerdp2:2.11.7-7.el9_8.7ALSA-2026:66347
AlmaLinux:10freerdp-devel2:3.10.3-12.el10_2.11ALSA-2026:66349
AlmaLinux:8freerdp-devel2:2.11.7-13.el8_10ALSA-2026:69387
AlmaLinux:9freerdp-devel2:2.11.7-7.el9_8.7ALSA-2026:66347
AlmaLinux:10freerdp-libs2:3.10.3-12.el10_2.11ALSA-2026:66349
AlmaLinux:8freerdp-libs2:2.11.7-13.el8_10ALSA-2026:69387
AlmaLinux:9freerdp-libs2:2.11.7-7.el9_8.7ALSA-2026:66347
AlmaLinux:10freerdp-server2:3.10.3-12.el10_2.11ALSA-2026:66349
AlmaLinux:10libwinpr2:3.10.3-12.el10_2.11ALSA-2026:66349
AlmaLinux:8libwinpr2:2.11.7-13.el8_10ALSA-2026:69387
AlmaLinux:9libwinpr2:2.11.7-7.el9_8.7ALSA-2026:66347
AlmaLinux:10libwinpr-devel2:3.10.3-12.el10_2.11ALSA-2026:66349
AlmaLinux:8libwinpr-devel2:2.11.7-13.el8_10ALSA-2026:69387
AlmaLinux:9libwinpr-devel2:2.11.7-7.el9_8.7ALSA-2026:66347
Alpine:v3.24freerdp3.27.1-r0ALPINE-CVE-2026-55193
Debian:12freerdp2no fix listedDEBIAN-CVE-2026-55193
Debian:13freerdp3no fix listedDEBIAN-CVE-2026-55193
Debian:14freerdp33.27.0+dfsg-1DEBIAN-CVE-2026-55193
Rocky Linux:10freerdp2:3.10.3-12.el10_2.11RLSA-2026:66349
Rocky Linux:8freerdp2:2.11.7-13.el8_10RLSA-2026:69387
Rocky Linux:9freerdp2:2.11.7-7.el9_8.7RLSA-2026:66347
Ubuntu:22.04:LTSfreerdp2no fix listedUBUNTU-CVE-2026-55193
Ubuntu:24.04:LTSfreerdp33.30.0+dfsg-0ubuntu0.24.04.1UBUNTU-CVE-2026-55193
Ubuntu:24.04:LTSfreerdp33.30.0+dfsg-0ubuntu0.24.04.1USN-8561-1
Ubuntu:25.10freerdp3no fix listedUBUNTU-CVE-2026-55193
Ubuntu:26.04:LTSfreerdp33.30.0+dfsg-0ubuntu0.26.04.1USN-8561-1
Ubuntu:26.04:LTSfreerdp33.30.0+dfsg-0ubuntu0.26.04.1UBUNTU-CVE-2026-55193

Affected products (as reported)

VendorProductVersions
FreeRDP FreeRDP < 3.27.0

Weakness: CWE-122 · 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

References