CVE-2026-91955 FreeRDP before 3.31.0 Denial of Service via Desktop Dimensions
Remote attackers can crash the FreeRDP server by sending crafted RDP packets with invalid desktop dimensions, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-91955?
CVE-2026-91955 is a high-severity denial of service vulnerability in Freerdp Freerdp, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
FreeRDP before 3.31.0 fails to validate client-supplied DesktopWidth and DesktopHeight values during GCC negotiation, allowing remote attackers to crash the server. Attackers can send crafted RDP packets with zero or oversized dimensions to trigger division-by-zero or assertion failures in multifragment update capability calculations, terminating the server process.
Weakness: CWE-369
Which versions are affected by CVE-2026-91955?
It affects 1 product.
Products include Freerdp Freerdp.
How do I fix CVE-2026-91955?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-91955 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-91955 exists.
Other vulnerabilities in Freerdp Freerdp
- CVE-2021-37594 Other in n/a
- CVE-2021-37595 Other in n/a
- CVE-2026-67305 FreeRDP Windows Client before 3.29.0 Heap Buffer Overflow via Cliprdr
- CVE-2026-66402 FreeRDP before 3.29.0 TLS Certificate Identity Validation Bypass
- CVE-2026-67289 FreeRDP before 3.29.0 HTTP Proxy Request Injection via Redirection
Sources
Also known as DEBIAN-CVE-2026-91955, GHSA-3hqr-g437-cr9w, GHSA-4464-r7qj-pgrx, UBUNTU-CVE-2026-91955.