CVE-2026-44421 Details
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.
A heap-buffer-overflow vulnerability has been identified in the FreeRDP client, affecting versions prior to 3.26.0. The issue arises in the handling of RDPGFX PDUs, where a malicious RDP server can exploit the FreeRDP client by sending crafted graphics data. The vulnerability is located in the 'gdi_CacheToSurface' function, which improperly validates destination rectangles. Although the rectangle edges are clamped to UINT16_MAX, the actual data copy uses the original unvalidated dimensions, leading to out-of-bounds heap writes. This flaw can cause crashes or potentially allow code execution within the client. The vulnerability is only exploitable when the client has RDPGFX enabled.
Users should update to FreeRDP version 3.26.0 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 1, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://access.redhat.com/errata/RHSA-2026:36203 | redhat-SADP | |
| https://access.redhat.com/errata/RHSA-2026:46393 | redhat-SADP | |
| https://access.redhat.com/security/cve/CVE-2026-44421 | redhat-SADP | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2483471 | redhat-SADP | |
| https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44421.json | redhat-SADP | |
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff | CISA-ADP | ExploitMitigationVendor Advisory |
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff | [email protected] | ExploitMitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-122 | Heap-based Buffer Overflow | [email protected] |
| CWE-787 | Out-of-bounds Write | redhat-SADP |
Affected Products
| Product | Versions |
|---|---|
| freerdp freerdp | < 3.26.0 |
CPE
Remediation
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Change History
11 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 27, 2026 | CVE Modified | redhat-SADP |
| Jul 22, 2026 | CVE Translated | [email protected] |
| Jul 17, 2026 | CVE Modified | redhat-SADP |
| Jul 15, 2026 | CVE Modified | redhat-SADP |
| Jul 8, 2026 | CVE Modified | redhat-SADP |
| Jun 30, 2026 | CVE Modified | redhat-SADP |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 1, 2026 | CVE Modified | CISA-ADP |
| Jun 1, 2026 | Initial Analysis | [email protected] |
| May 29, 2026 | New CVE Received | [email protected] |