CVE-2026-91963 FreeRDP 2.0.0 through 3.30.0 Uninitialized Heap Memory Disclosure via urbdrc
A malicious RDP server can read uninitialized heap memory from FreeRDP clients, defeating ASLR and aiding remote code execution attacks.
- 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-2026-91963?
CVE-2026-91963 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 uninitialized heap memory disclosure vulnerability in the urbdrc USB redirection channel. A malicious RDP server can induce failing USB transfers to read uninitialized heap memory from the client, defeating ASLR and enabling remote code execution when chained with memory corruption vulnerabilities.
Weakness: CWE-457
Which versions are affected by CVE-2026-91963?
It affects 1 product.
Products include Freerdp Freerdp.
How do I fix CVE-2026-91963?
Upgrade to a fixed version.
Is CVE-2026-91963 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-91963 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-2026-91963, GHSA-hw7p-5h2r-83gq, GHSA-v76r-r3hh-2mwm, UBUNTU-CVE-2026-91963.