Vulnerability · Published Oct 13, 2026 · Assigned by VulnCheck

CVE-2026-109952FreeRDP 3.0.0 before 3.32.0 Security Protocol Downgrade via Negotiation Response

Medium 5.3

In plain English

A medium-severity security flaw in FreeRDP from FreeRDP. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.3%top 74.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

The FreeRDP client 3.0.0 before 3.32.0 does not check a server-selected PROTOCOL_RDSTLS or PROTOCOL_HYBRID_EX against its enabled protocol set in nego_process_negotiation_response(), allowing a security protocol downgrade. A malicious server or man-in-the-middle can select RDSTLS to override /sec:nla pinning, complete authentication with an all-zero cookie, and receive the user's cleartext password in the Client Info PDU.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	freerdp2	no fix listed	DEBIAN-CVE-2026-109952
Debian:13	freerdp3	no fix listed	DEBIAN-CVE-2026-109952
Debian:14	freerdp3	3.32.0+dfsg-1	DEBIAN-CVE-2026-109952
Ubuntu:22.04:LTS	freerdp2	no fix listed	UBUNTU-CVE-2026-109952
Ubuntu:24.04:LTS	freerdp3	3.32.0+dfsg-0ubuntu0.24.04.1	UBUNTU-CVE-2026-109952
Ubuntu:26.04:LTS	freerdp3	3.32.0+dfsg-0ubuntu0.26.04.1	UBUNTU-CVE-2026-109952

Affected products (as reported)

Vendor	Product	Versions
FreeRDP	FreeRDP	3.0.0 – before 3.32.0

Weakness: CWE-757 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N

References

GitHub Security Advisory (GHSA-qq23-mqmv-pc65) vendor-advisory
VulnCheck Advisory: FreeRDP 3.0.0 before 3.32.0 Security Protocol Downgrade via Negotiation Response third-party-advisory