CVE-2026-25959 - Vulnerability Analysis
CriticalCVSS: 9.8Last Updated: February 27, 2026
FreeRDP - Use After Free
Published: February 25, 2026Updated: February 27, 2026PoC AvailableRemote Exploitable
Overview
FreeRDP < 3.23.0 contains a use after free vulnerability caused by concurrent access to clipboard data in xf_cliprdr_provide_data_ and X11 event threads, letting remote attackers cause heap corruption, exploit requires concurrent clipboard usage.
Severity & Score
Severity: Critical
CVSS Score: 9.8
Impact
Attackers can cause heap corruption leading to potential application crashes or arbitrary code execution.
Mitigation
Update to version 3.23.0 or later.
References
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L1337-L1344
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L200-L208
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L2295
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L2323-L2334
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L933
- https://github.com/FreeRDP/FreeRDP/commit/d3e8b3b9365be96a4f11dda149d71b3287227d0a
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-78xg-v4p2-4w3c
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L1229-L1243
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L2363
Related Resources
Details
- CVE ID
- CVE-2026-25959
- Severity
- Critical
- CVSS Score
- 9.8
- Type
- use_after_free
- Status
- confirmed
CWE
- CWE-416
CVSS Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H