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FreeRDP before 3.29.0 Use-After-Free via async message proxy

Type: advisorySources: OSV

FreeRDP before 3.29.0 contains client-side heap use-after-free vulnerabilities in the async update message proxy for RAIL WINDOW_STATE_ORDER and NOTIFY_ICON_STATE_ORDER when AsyncUpdate is enabled. When a malicious or compromised RDP server sends crafted update orders, the message proxy shallow-copies structures containing nested parser-owned pointers (e.g., titleInfo.string, windowRects, visibilityRects, icon buffers). The parser frees those nested buffers after the callback returns, so the queued async message later dispatches stale pointers, potentially causing memory corruption or a client crash.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-67300
Confirmed fixed CVEs
Not specified
Updated in this feed
8 Nov 2026, 01:20 UTC · Revision 1

Source evidence

FreeRDP before 3.29.0 Use-After-Free via async message proxy

core-osv · Original source

Published 1 Aug 2026, 12:22 UTC

FreeRDP before 3.29.0 contains client-side heap use-after-free vulnerabilities in the async update message proxy for RAIL WINDOW_STATE_ORDER and NOTIFY_ICON_STATE_ORDER when AsyncUpdate is enabled. When a malicious or compromised RDP server sends crafted update orders, the message proxy shallow-copies structures containing nested parser-owned pointers (e.g., titleInfo.string, windowRects, visibilityRects, icon buffers). The parser frees those nested buffers after the callback returns, so the queued async message later dispatches stale pointers, potentially causing memory corruption or a client crash.

osv:CVE-2026-67300
Complete source record
{
  "id": "9a663229defb94eb4fd88f46cc3dc07771dd2490094750d5255645fe567ee853",
  "url": "https://osv.dev/vulnerability/CVE-2026-67300",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "FreeRDP before 3.29.0 Use-After-Free via async message proxy",
    "summary": "FreeRDP before 3.29.0 contains client-side heap use-after-free vulnerabilities in the async update message proxy for RAIL WINDOW_STATE_ORDER and NOTIFY_ICON_STATE_ORDER when AsyncUpdate is enabled. When a malicious or compromised RDP server sends crafted update orders, the message proxy shallow-copies structures containing nested parser-owned pointers (e.g., titleInfo.string, windowRects, visibilityRects, icon buffers). The parser frees those nested buffers after the callback returns, so the queued async message later dispatches stale pointers, potentially causing memory corruption or a client crash.",
    "evidence": "osv:CVE-2026-67300",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-67300",
      "aliases": [
        "CVE-2026-67300",
        "GHSA-33gg-h66j-3697"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/freerdp/freerdp",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "743f437f434c6814d3ba265c75cab14673bc2911"
                },
                {
                  "fixed": "5370fb26fbf034ecd11d3026b6ad639b5fff493f"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.29.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "fixed": "5370fb26fbf034ecd11d3026b6ad639b5fff493f"
                      }
                    ],
                    "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-2026-67300.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:52.375512736Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67300.json",
        "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-33gg-h66j-3697",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-67300",
        "https://www.vulncheck.com/advisories/freerdp-before-use-after-free-via-async-message-proxy",
        "https://github.com/FreeRDP/FreeRDP/commit/5370fb26fbf034ecd11d3026b6ad639b5fff493f"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-416"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67300.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-67300",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 521287,
  "published_at": "2026-08-01T12:22:18.315+00:00"
}