CVE-2026-91956 FreeRDP before 3.31.0 Out-of-Bounds Read via URBDRC
A malicious RDP server can trigger an out-of-bounds read in FreeRDP clients, causing a crash or potential memory disclosure.
- 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-2026-91956?
CVE-2026-91956 is a high-severity memory corruption 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 before 3.31.0 contains an out-of-bounds read vulnerability in the URBDRC channel's func_get_ep_desc function that indexes interface arrays by position instead of protocol field InterfaceNumber. A malicious RDP server can send a crafted SELECT_CONFIGURATION message with permuted InterfaceNumber values to read past allocated heap memory and crash the client.
Weakness: CWE-125
Which versions are affected by CVE-2026-91956?
It affects 1 product.
Products include Freerdp Freerdp.
How do I fix CVE-2026-91956?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-91956 being exploited?
There is no known exploitation of CVE-2026-91956 in the wild and no public exploit code.
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-2026-91956, GHSA-hg4r-vv53-vwf8, GHSA-mh85-h6g9-mfcc, UBUNTU-CVE-2026-91956.