CVE-2026-27624

{
  "id": "CVE-2026-27624",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-27624",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-02-25T15:09:17.451722Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 7.2,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 2.7,
        "exploitabilityScore": 3.9
      },
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 6.5,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 2.5,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "coturn",
          "product": "coturn",
          "versions": [
            {
              "status": "affected",
              "version": "< 4.9.0"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-02-25T05:17:25.380",
  "references": [
    {
      "url": "https://github.com/coturn/coturn/commit/b80eb898ba26552600770162c26a8ae7f3661b0b",
      "tags": [
        "Patch"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/coturn/coturn/security/advisories/GHSA-6g6j-r9rf-cm7p",
      "tags": [
        "Not Applicable"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/coturn/coturn/security/advisories/GHSA-j8mm-mpf8-gvjg",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/coturn/coturn/security/advisories/GHSA-6g6j-r9rf-cm7p",
      "tags": [
        "Not Applicable"
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    },
    {
      "url": "https://github.com/coturn/coturn/security/advisories/GHSA-j8mm-mpf8-gvjg",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-284"
        },
        {
          "lang": "en",
          "value": "CWE-441"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Coturn is a free open source implementation of TURN and STUN Server. Coturn is commonly configured to block loopback and internal ranges using \"denied-peer-ip\" and/or default loopback restrictions. CVE-2020-26262 addressed bypasses involving \"0.0.0.0\", \"[::1]\" and \"[::]\", but IPv4-mapped IPv6 is not covered. When sending a \"CreatePermission\" or \"ChannelBind\" request with the \"XOR-PEER-ADDRESS\" value of \"::ffff:127.0.0.1\", a successful response is received, even though \"127.0.0.0/8\" is blocked via \"denied-peer-ip\". The root cause is that, prior to the updated fix implemented in version 4.9.0, three functions in \"src/client/ns_turn_ioaddr.c\" do not check \"IN6_IS_ADDR_V4MAPPED\". \"ioa_addr_is_loopback()\" checks \"127.x.x.x\" (AF_INET) and \"::1\" (AF_INET6), but not \"::ffff:127.0.0.1.\" \"ioa_addr_is_zero()\" checks \"0.0.0.0\" and \"::\", but not \"::ffff:0.0.0.0.\" \"addr_less_eq()\" used by \"ioa_addr_in_range()\" for \"denied-peer-ip\" matching: when the range is AF_INET and the peer is AF_INET6, the comparison returns 0 without extracting the embedded IPv4. Version 4.9.0 contains an updated fix to address the bypass of the fix for CVE-2020-26262."
    },
    {
      "lang": "es",
      "value": "Coturn es una implementación de código abierto gratuita de servidor TURN y STUN. Coturn se configura comúnmente para bloquear rangos de loopback e internos usando 'denied-peer-ip' y/o restricciones de loopback predeterminadas. CVE-2020-26262 abordó evasiones que involucran '0.0.0.0', '[::1]' y '[::]', pero IPv6 mapeado a IPv4 no está cubierto. Al enviar una solicitud 'CreatePermission' o 'ChannelBind' con el valor 'XOR-PEER-ADDRESS' de '::ffff:127.0.0.1', se recibe una respuesta exitosa, aunque '127.0.0.0/8' está bloqueado a través de 'denied-peer-ip'. La causa raíz es que, antes de la corrección actualizada implementada en la versión 4.9.0, tres funciones en 'src/client/ns_turn_ioaddr.c' no verifican 'IN6_IS_ADDR_V4MAPPED'. 'ioa_addr_is_loopback()' verifica '127.x.x.x' (AF_INET) y '::1' (AF_INET6), pero no '::ffff:127.0.0.1'. 'ioa_addr_is_zero()' verifica '0.0.0.0' y '::', pero no '::ffff:0.0.0.0'. 'addr_less_eq()' utilizada por 'ioa_addr_in_range()' para la coincidencia de 'denied-peer-ip': cuando el rango es AF_INET y el par es AF_INET6, la comparación devuelve 0 sin extraer el IPv4 incrustado. La versión 4.9.0 contiene una corrección actualizada para abordar la evasión de la corrección para CVE-2020-26262."
    }
  ],
  "lastModified": "2026-06-17T10:27:24.603",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:coturn_project:coturn:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "5C4DE18B-B9AA-4314-B584-7BA316D5D7DB",
              "versionEndExcluding": "4.9.0"
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          "operator": "OR"
        }
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  "sourceIdentifier": "security-advisories@github.com"
}