Client crash via stale XImage surface pointer
Published Feb 25, 2026 · Updated Feb 25, 2026
Use-after-free in FreeRDP before 3.23.0 allows remote attackers controlling RDP servers to crash X11 clients via crafted surface updates. xf_AppUpdateWindowFromSurface caches an XImage that aliases surface->data, but gdi_DeleteSurface frees that buffer without invalidating the cached image, so XPutImage later reads freed heap memory. The client must connect with software GDI, RDPGFX, and RemoteApp enabled; the server must delete and recreate a same-sized surface with the same identifier.
Summary
What happened
Use-after-free in FreeRDP before 3.23.0 allows remote attackers controlling RDP servers to crash X11 clients via crafted surface updates. xf_AppUpdateWindowFromSurface caches an XImage that aliases surface->data, but gdi_DeleteSurface frees that buffer without invalidating the cached image, so XPutImage later reads freed heap memory. The client must connect with software GDI, RDPGFX, and RemoteApp enabled; the server must delete and recreate a same-sized surface with the same identifier.
The record
- CVE
- CVE-2026-25955
- Published
- Feb 25, 2026
- Updated
- Feb 25, 2026
- Vendor
- FreeRDP
- Product
- FreeRDP
- Classifications
- CWE-416, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 25, 2026CVE publishedPublication date reported by the CVE source.
- Feb 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.23.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- FreeRDP stale XImage proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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