FreeRDP – Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass_CVE-2026-40033

{
    "lastseen": "",
    "description": "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.",
    "published": "2026-05-26T14:08:47.535Z",
    "modified": "2026-05-26T15:21:18.084Z",
    "type": "cve",
    "title": "FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass",
    "source": "VulnCheck",
    "references": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff\nhttps://github.com/FreeRDP/FreeRDP/commit/23b36cd00ebf0ccd97750fcdbc9aa2f362352da7\nhttps://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-in-gdi-cachetosurface-via-rectangle-validation-bypass",
    "id": "CVE-2026-40033",
    "bulletinFamily": "",
    "cwe": [
        "CWE-122"
    ],
    "cvelist": null,
    "sourceData": "FreeRDP FreeRDP 0",
    "sourceHref": "",
    "cvss": {
        "score": 8.6,
        "severity": "HIGH",
        "vector": "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",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "FreeRDP",
    "version": "0",
    "vendor": "FreeRDP",
    "ai_description": "Heap-buffer-overflow vulnerability in gdi_CacheToSurface allowing remote attackers to write out-of-bounds heap memory",
    "ai_severity": "High",
    "ai_vendor": "FreeRDP",
    "ai_product": "FreeRDP",
    "ai_version": "before 3.26.0",
    "ai_score": 8.6
}