{"id":"CVE-2026-40033","title":"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","summary":"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…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cwe":["CWE-122","CWE-787"],"vendor":"freerdp","product":"freerdp","affected":["freerdp < 3.26.0"],"patched":["freerdp 3.26.0"],"published":"2026-05-26","updated":"2026-07-08","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-40033","references":[{"url":"https://github.com/FreeRDP/FreeRDP/commit/d7508ebcd82842a691ae4941e5104d14240a89ae","label":"disclosure@vulncheck.com"},{"url":"https://github.com/FreeRDP/FreeRDP/pull/12713","label":"disclosure@vulncheck.com"},{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-in-gdi-cachetosurface-via-rectangle-validation-bypass","label":"disclosure@vulncheck.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:36203","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/security/cve/CVE-2026-40033","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2481473","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40033.json","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}],"tags":["nvd"],"epss":0.01037,"epssPercentile":0.61911,"ingestedAt":"2026-07-08T13:51:10.770Z","slug":"CVE-2026-40033","body":"## Overview\n\nFreeRDP 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.\n\n## Affected\n\n- `freerdp < 3.26.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `freerdp 3.26.0`","depth":"twilight","depthScore":49,"depthScoreParts":{"impact":48.4,"likelihood":0.2,"exploitation":0,"ransomware":0},"changes":[]}