CVE-2026-25959 FreeRDP has heap-use-after-free in xf_cliprdr_provide_data_
A race condition in FreeRDP's clipboard handling allows attackers to trigger a heap use-after-free, potentially leading to code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-25959?
CVE-2026-25959 is a medium-severity use after free vulnerability in Freerdp Freerdp, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_cliprdr_provide_data_` passes freed `pDstData` to `XChangeProperty` because the cliprdr channel thread calls `xf_cliprdr_server_format_data_response` which converts and uses the clipboard data without holding any lock, while the X11 event thread concurrently calls `xf_cliprdr_clear_cached_data` → `HashTable_Clear` which frees the same data via `xf_cached_data_free`, triggering a heap use after free. Version 3.23.0 fixes the issue.
Weakness: CWE-416
Which versions are affected by CVE-2026-25959?
It affects 1 product.
Products include Freerdp Freerdp.
How do I fix CVE-2026-25959?
Upgrade to a fixed version.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-25959 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-25959 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-2026-25959, GHSA-78xg-v4p2-4w3c, MINI-rrvv-42rg-fghx, UBUNTU-CVE-2026-25959.