CVE-2026-109939 FreeRDP 3.27.1 before 3.32.0 NULL Pointer Dereference via Cache Bitmap V3 Order
A malicious RDP server can crash a connecting FreeRDP client by sending a specific order when the non-default Bitmap Cache V3 feature is enabled.
- 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-2026-109939?
CVE-2026-109939 is a high-severity vulnerability in Freerdp Freerdp, published on 13 Oct 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 3.27.1 before 3.32.0 contains a NULL pointer dereference in update_read_cache_bitmap_v3_order() in libfreerdp/core/orders.c, which accesses the client bitmap cache when the CBR3_DO_NOT_CACHE flag is set, even though the cache is not yet initialized before Demand Active. A malicious or compromised RDP server can send a Cache Bitmap V3 order during connection setup to crash a connecting client that has enabled the non-default Bitmap Cache V3 feature (/cache:codec:<rfx|nsc|jpeg>).
Weakness: CWE-476
Which versions are affected by CVE-2026-109939?
It affects 1 product.
Products include Freerdp Freerdp.
How do I fix CVE-2026-109939?
Upgrade to a fixed version.
Is CVE-2026-109939 being exploited?
There is no known exploitation of CVE-2026-109939 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-2026-109939, GHSA-93pr-x2pm-jv23, GHSA-cq4m-gwc5-w8rc, UBUNTU-CVE-2026-109939.