{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-27624",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-02-20T22:02:30.027Z",
        "datePublished": "2026-02-25T04:04:17.009Z",
        "dateUpdated": "2026-02-25T15:09:21.716Z"
    },
    "containers": {
        "cna": {
            "title": "Coturn: IPv4-mapped IPv6 (::ffff:0:0/96) bypasses denied-peer-ip ACL",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-284",
                            "lang": "en",
                            "description": "CWE-284: Improper Access Control",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-441",
                            "lang": "en",
                            "description": "CWE-441: Unintended Proxy or Intermediary ('Confused Deputy')",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 7.2,
                        "baseSeverity": "HIGH",
                        "confidentialityImpact": "LOW",
                        "integrityImpact": "LOW",
                        "privilegesRequired": "NONE",
                        "scope": "CHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/coturn/coturn/security/advisories/GHSA-j8mm-mpf8-gvjg",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/coturn/coturn/security/advisories/GHSA-j8mm-mpf8-gvjg"
                },
                {
                    "name": "https://github.com/coturn/coturn/security/advisories/GHSA-6g6j-r9rf-cm7p",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/coturn/coturn/security/advisories/GHSA-6g6j-r9rf-cm7p"
                },
                {
                    "name": "https://github.com/coturn/coturn/commit/b80eb898ba26552600770162c26a8ae7f3661b0b",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/coturn/coturn/commit/b80eb898ba26552600770162c26a8ae7f3661b0b"
                }
            ],
            "affected": [
                {
                    "vendor": "coturn",
                    "product": "coturn",
                    "versions": [
                        {
                            "version": "< 4.9.0",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-02-25T04:04:17.009Z"
            },
            "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."
                }
            ],
            "source": {
                "advisory": "GHSA-j8mm-mpf8-gvjg",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/coturn/coturn/security/advisories/GHSA-6g6j-r9rf-cm7p",
                        "tags": [
                            "exploit"
                        ]
                    },
                    {
                        "url": "https://github.com/coturn/coturn/security/advisories/GHSA-j8mm-mpf8-gvjg",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-02-25T15:09:17.451722Z",
                                "id": "CVE-2026-27624",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "yes"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-02-25T15:09:21.716Z"
                }
            }
        ]
    }
}