CVE-2026-91964 FreeRDP 2.0.0 through 3.30.0 Heap Buffer Overflow via RoutingToken
A malicious RDP server can trigger a heap buffer overflow in FreeRDP clients, potentially leading to code execution or crashes.
- 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-2026-91964?
CVE-2026-91964 is a high-severity memory corruption vulnerability in 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 a heap-based buffer overflow in nego_send_negotiation_request when processing Server Redirection PDU messages with attacker-controlled LoadBalanceInfo fields. A malicious RDP server can trigger the overflow by sending an arbitrary-length field that gets written to a fixed 512-byte buffer without validation, causing client crashes or potential code execution when chained with memory disclosure.
Weakness: CWE-122
Which versions are affected by CVE-2026-91964?
How do I fix CVE-2026-91964?
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-2026-91964 being exploited?
There is no known exploitation of CVE-2026-91964 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-91964, GHSA-2vf2-grvj-6g8x, GHSA-f73m-4rv5-6gp4, UBUNTU-CVE-2026-91964.