{
  "cveId": "CVE-2026-43994",
  "url": "https://patchblox.com/security/cve/CVE-2026-43994",
  "summary": "CVE-2026-43994 is fixed in coturn on 1 platform by DEBIAN-CVE-2026-43994 (version 4.12.0-1), released July 4, 2026. It is not reported as exploited. Patch Radar priority: Urgent.",
  "title": "coturn: Coturn is a free open source implementation of TURN and STUN Server",
  "description": "Coturn is a free open source implementation of TURN and STUN Server. Versions prior to 4.10.0 contain a stack buffer overflow in decode_oauth_token_gcm(). A uint16_t nonce_len field read from an attacker-supplied OAuth access token (0-65535) is passed directly to memcpy() as the copy length into a 256-byte stack buffer (oauth_encrypted_block.nonce[256]) without bounds checking. The overflow occurs before AES-GCM authentication is verified, the attacker does not need to know the OAuth key or produce a valid AES-GCM token. Up to 735 bytes of attacker-controlled data are written past the buffer, may corrupt adjacent stack data, including control-flow data depending on compiler, ABI, and mitigations. Requires --oauth mode (non-default). This may provide a plausible RCE primitive depending on exploit mitigations; because coturn is widely deployed for WebRTC TURN/STUN and --oauth is commonly recommended, impact can be broad. This issue has been fixed in version 4.10.0.",
  "published": "2026-06-18T21:16:28Z",
  "severity": "critical",
  "cvss": 9.8,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00675,
  "epssPercentile": 0.52432,
  "priority": "Urgent",
  "priorityTier": 2,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "coturn",
      "release": "Debian 14",
      "fixedVersion": "4.12.0-1",
      "fix": "DEBIAN-CVE-2026-43994",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-43994",
      "released": "2026-07-04T15:03:22Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}