Transmission 4.0.0 before 4.1.3 Permissive CORS Leaks RPC Anti-CSRF Token

{
  "id": "865a14ea14058deaaf156d503fc0be2d2630b2362ba14a12b6b8eceba3fdf9b3",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-116748",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Transmission 4.0.0 before 4.1.3 Permissive CORS Leaks RPC Anti-CSRF Token",
    "summary": "Transmission 4.0.0 before 4.1.3 contains a permissive CORS vulnerability in handle_request() in rpc-server.cc that exposes the X-Transmission-Session-Id anti-CSRF token to any web origin. Malicious web pages can read the token from the 409 handshake response and replay it to issue RPC calls, enabling script-torrent-done execution, download-dir changes, or torrent and data deletion.",
    "evidence": "cve:CVE-2026-116748",
    "products": [
      {
        "name": {
          "value": "transmission",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-116748",
      "aliases": [
        "CVE-2026-116748"
      ],
      "metrics": [
        {
          "format": "CVSS",
          "cvssV4_0": {
            "version": "4.0",
            "baseScore": 8.7,
            "attackVector": "NETWORK",
            "baseSeverity": "HIGH",
            "vectorString": "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",
            "userInteraction": "PASSIVE",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "privilegesRequired": "NONE",
            "subIntegrityImpact": "NONE",
            "vulnIntegrityImpact": "HIGH",
            "subAvailabilityImpact": "NONE",
            "vulnAvailabilityImpact": "HIGH",
            "subConfidentialityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH"
          }
        },
        {
          "format": "CVSS",
          "cvssV3_1": {
            "scope": "UNCHANGED",
            "version": "3.1",
            "baseScore": 8.8,
            "attackVector": "NETWORK",
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
            "integrityImpact": "HIGH",
            "userInteraction": "REQUIRED",
            "attackComplexity": "LOW",
            "availabilityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "confidentialityImpact": "HIGH"
          }
        }
      ],
      "affected": [
        {
          "repo": "https://github.com/transmission/transmission",
          "vendor": "transmission",
          "product": "transmission",
          "versions": [
            {
              "status": "affected",
              "version": "4.0.0",
              "lessThan": "4.1.3",
              "versionType": "semver"
            }
          ],
          "packageURL": "pkg:github/transmission/transmission",
          "defaultStatus": "unaffected"
        }
      ],
      "modified": "2026-10-26T21:52:45.799Z",
      "provider": "cve",
      "references": [
        "https://github.com/transmission/transmission/pull/8938",
        "https://github.com/transmission/transmission/commit/c6a1bd2017a0fea9c956737c213f23e4b0f7929e",
        "https://github.com/transmission/transmission",
        "https://github.com/transmission/transmission/releases/tag/4.1.3",
        "https://github.com/transmission/transmission/blob/4.1.2/libtransmission/rpc-server.cc#L560",
        "https://joshua.hu/transmission-cors-rpc-csrf-rce-drive-by-exploit",
        "https://www.vulncheck.com/advisories/transmission-4.0.0-before-4.1.3-permissive-cors-leaks-rpc-anti-csrf-token"
      ],
      "provider_metadata": {
        "cna": {
          "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
          "shortName": "VulnCheck",
          "dateUpdated": "2026-10-26T21:52:45.799Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-116748",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 353943,
  "published_at": "2026-10-26T21:52:45.799+00:00"
}