CVE-2026-91958 FreeRDP 3.11.0 through 3.30.0 Heap Buffer Overflow via Monitor Index
Attackers can trigger heap buffer overflows in FreeRDP by crafting malicious RDP files with invalid monitor indices, potentially leading to code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-91958?
CVE-2026-91958 is a medium-severity memory corruption vulnerability in Freerdp Freerdp, published on 15 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
FreeRDP versions before 3.31.0 fail to validate MonitorIds array values when parsing RDP connection files, allowing unbounded array indexing in xf_detect_monitors. Attackers can craft a malicious RDP file with an out-of-range selectedmonitors value to trigger out-of-bounds heap read and write operations when opened in xfreerdp.
Weakness: CWE-125
Which versions are affected by CVE-2026-91958?
It affects 1 product.
Products include Freerdp Freerdp.
How do I fix CVE-2026-91958?
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-2026-91958 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-91958 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-2026-91958, GHSA-23pf-q83q-x45r, GHSA-qjqr-mv8g-x357, UBUNTU-CVE-2026-91958.