{
  "cveId": "CVE-2020-26262",
  "url": "https://patchblox.com/security/cve/CVE-2020-26262",
  "summary": "CVE-2020-26262 is fixed in coturn on 1 platform, first by coturn 4.5.0.7-1ubuntu2.18.04.3, released January 10, 2021. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "coturn: Coturn is free open source implementation of TURN and STUN Server",
  "description": "Coturn is free open source implementation of TURN and STUN Server. Coturn before version 4.5.2 by default does not allow peers to connect and relay packets to loopback addresses in the range of \u0060127.x.x.x\u0060. However, it was observed that when sending a \u0060CONNECT\u0060 request with the \u0060XOR-PEER-ADDRESS\u0060 value of \u00600.0.0.0\u0060, a successful response was received and subsequently, \u0060CONNECTIONBIND\u0060 also received a successful response. Coturn then is able to relay packets to the loopback interface. Additionally, when coturn is listening on IPv6, which is default, the loopback interface can also be reached by making use of either \u0060[::1]\u0060 or \u0060[::]\u0060 as the peer address. By using the address \u00600.0.0.0\u0060 as the peer address, a malicious user will be able to relay packets to the loopback interface, unless \u0060--denied-peer-ip=0.0.0.0\u0060 (or similar) has been specified. Since the default configuration implies that loopback peers are not allowed, coturn administrators may choose to not set the \u0060denied-peer-ip\u0060 setting. The issue patched in version 4.5.2. As a workaround the addresses in the address block \u00600.0.0.0/8\u0060, \u0060[::1]\u0060 and \u0060[::]\u0060 should be denied by default unless \u0060--allow-loopback-peers\u0060 has been specified.",
  "published": "2021-01-10T16:00:00Z",
  "severity": "Medium",
  "epss": 0.01547,
  "epssPercentile": 0.75172,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "coturn",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "4.5.0.7-1ubuntu2.18.04.3",
      "fix": "coturn 4.5.0.7-1ubuntu2.18.04.3",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-coturn-4.5.0.7-1ubuntu2.18.04.3",
      "released": "2021-01-10T16:00:00Z"
    },
    {
      "platform": "linux",
      "product": "coturn",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "4.5.1.1-1.1ubuntu0.20.04.2",
      "fix": "coturn 4.5.1.1-1.1ubuntu0.20.04.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-coturn-4.5.1.1-1.1ubuntu0.20.04.2",
      "released": "2021-01-10T16:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}