CVE-2026-91960 FreeRDP before 3.31.0 Integer Overflow Double Free
Remote attackers can crash the FreeRDP client via a crafted WebSocket Ping frame triggering an integer overflow and double free.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-91960?
CVE-2026-91960 is a high-severity vulnerability in Freerdp Freerdp, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
FreeRDP versions before 3.31.0 contain an integer overflow in WinPR's Stream_EnsureRemainingCapacity function that allows remote attackers to cause denial of service. A malicious RD Gateway peer can send a WebSocket Ping frame with a crafted 64-bit extended payload length to trigger integer wraparound, resulting in a double free that crashes the FreeRDP client during connection.
Weakness: CWE-190
Which versions are affected by CVE-2026-91960?
It affects 1 product.
Products include Freerdp Freerdp.
How do I fix CVE-2026-91960?
Upgrade to a fixed version.
Is CVE-2026-91960 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-91960 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-2026-91960, GHSA-7w2c-f8mf-gfr7, GHSA-vccg-35r5-8jrf, UBUNTU-CVE-2026-91960.