FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.6epss 1.0%
exploitation probability
1.0%top 38% of all CVEs
observed exploitation
nono source reports it
FreeRDP before 3.26.0 contains a heap-buffer-overflow vulnerability in gdi_CacheToSurface that allows remote attackers to write out-of-bounds heap memory. The vulnerability occurs because rectangle validation clamps coordinates to UINT16_MAX but performs copy operations using unclamped cache entry dimensions, enabling malicious RDP servers to trigger large out-of-bounds writes and potentially achieve remote code execution or client crash.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
FreeRDP · FreeRDPReferences
https://access.redhat.com/errata/RHSA-2026:36203https://access.redhat.com/errata/RHSA-2026:46393https://access.redhat.com/security/cve/CVE-2026-40033https://bugzilla.redhat.com/show_bug.cgi?id=2481473https://github.com/FreeRDP/FreeRDP/commit/d7508ebcd82842a691ae4941e5104d14240a89aehttps://github.com/FreeRDP/FreeRDP/pull/12713https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ffhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40033.jsonhttps://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-in-gdi-cachetosurface-via-rectangle-validation-bypass