Vulnerability Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client by sending crafted RDPGFX PDUs. The bug is in gdi_CacheToSurface: it validates a destination rectangle that is clamped to UINT16_MAX, but then performs the copy using the original cacheEntry->width/height. This can cause a large out-of-bounds heap write and may lead to client crashes or code execution. This bug is reachable from a malicious RDP server, but only when the client has RDPGFX enabled. This vulnerability is fixed in 3.26.0.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Freerdp | Freerdp | < 3.26.0 |
Related Weaknesses (CWE)
References
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ffExploitMitigationVendor Advisory
- https://access.redhat.com/errata/RHSA-2026:36203
- https://access.redhat.com/errata/RHSA-2026:46393
- https://access.redhat.com/security/cve/CVE-2026-44421
- https://bugzilla.redhat.com/show_bug.cgi?id=2483471
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ffExploitMitigationVendor Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44421.json
FAQ
What is CVE-2026-44421?
CVE-2026-44421 is a vulnerability with a CVSS score of 8.8 (HIGH). FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client by sending crafted RDPGFX PDUs. ...
How severe is CVE-2026-44421?
CVE-2026-44421 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-44421?
Check the references section above for vendor advisories and patch information. Affected products include: Freerdp Freerdp.