FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass

{
  "id": "0f6371c7faa6ed5964fbce164d92fc8c15013bac8a5fa3feddfbdebafc494afd",
  "url": "https://osv.dev/vulnerability/CVE-2026-40033",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass",
    "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_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.",
    "evidence": "osv:CVE-2026-40033",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-40033",
      "aliases": [
        "CVE-2026-40033",
        "CVE-2026-44421",
        "GHSA-p6r2-4hgm-m6ff"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "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": [
        {
          "ranges": [
            {
              "repo": "https://github.com/freerdp/freerdp",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "3f6d7cb1f8973cc84c66b258a9a61c4e2b2f30a6"
                },
                {
                  "fixed": "d7508ebcd82842a691ae4941e5104d14240a89ae"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.26.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "d7508ebcd82842a691ae4941e5104d14240a89ae"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "3.5.1",
            "3.5.0",
            "3.4.0",
            "3.3.0",
            "3.2.0",
            "3.1.0",
            "3.0.0",
            "3.0.0-rc0",
            "3.0.0-beta4",
            "3.0.0-beta3",
            "3.0.0-beta2",
            "3.0.0-beta1",
            "2.0.0",
            "2.0.0-rc4",
            "2.0.0-rc3",
            "2.0.0-rc2",
            "2.0.0-rc1",
            "2.0.0-rc0",
            "2.0.0-beta1+android11",
            "2.0.0-beta1+android10",
            "1.2.0-beta1+android9",
            "1.2.0-beta1+android7",
            "1.1.0-beta+2013071101",
            "1.1.0-beta1+ios4",
            "1.1.0-beta1+android5",
            "1.1.0-beta1+android4",
            "1.1.0-beta1+ios3",
            "1.1.0-beta1+ios2",
            "1.1.0-beta1+android3",
            "1.1.0-beta1+android2",
            "1.1.0-beta1+ios1",
            "1.1.0-beta1",
            "1.0.1",
            "1.0.0",
            "1.0-beta5",
            "1.0-beta4",
            "1.0-beta2",
            "1.0-beta1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-40033.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:24.922206914Z",
      "provider": "osv",
      "references": [
        "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40033.json",
        "https://access.redhat.com/errata/RHSA-2026:36203",
        "https://access.redhat.com/errata/RHSA-2026:46393",
        "https://access.redhat.com/security/cve/CVE-2026-40033",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40033.json",
        "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-40033",
        "https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-in-gdi-cachetosurface-via-rectangle-validation-bypass",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2481473",
        "https://github.com/FreeRDP/FreeRDP/pull/12713",
        "https://github.com/FreeRDP/FreeRDP/commit/d7508ebcd82842a691ae4941e5104d14240a89ae"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-122"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40033.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-40033",
        "evidence": "/id"
      },
      {
        "value": "CVE-2026-44421",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 491376,
  "published_at": "2026-05-26T14:08:47.535+00:00"
}