{"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"}}]}}

{}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:coturn_project:coturn:*:*:*:*:*:*:*:*", "matchCriteriaId": "5C4DE18B-B9AA-4314-B584-7BA316D5D7DB", "versionEndExcluding": "4.9.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "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 implementaci\u00f3n de c\u00f3digo abierto gratuita de servidor TURN y STUN. Coturn se configura com\u00fanmente para bloquear rangos de loopback e internos usando 'denied-peer-ip' y/o restricciones de loopback predeterminadas. CVE-2020-26262 abord\u00f3 evasiones que involucran '0.0.0.0', '[::1]' y '[::]', pero IPv6 mapeado a IPv4 no est\u00e1 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' est\u00e1 bloqueado a trav\u00e9s de 'denied-peer-ip'. La causa ra\u00edz es que, antes de la correcci\u00f3n actualizada implementada en la versi\u00f3n 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 comparaci\u00f3n devuelve 0 sin extraer el IPv4 incrustado. La versi\u00f3n 4.9.0 contiene una correcci\u00f3n actualizada para abordar la evasi\u00f3n de la correcci\u00f3n para CVE-2020-26262."}], "id": "CVE-2026-27624", "lastModified": "2026-02-27T18:04:29.457", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 3.9, "impactScore": 2.7, "source": "security-advisories@github.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 2.5, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2026-02-25T05:17:25.380", "references": [{"source": "security-advisories@github.com", "tags": ["Patch"], "url": "https://github.com/coturn/coturn/commit/b80eb898ba26552600770162c26a8ae7f3661b0b"}, {"source": "security-advisories@github.com", "tags": ["Not Applicable"], "url": "https://github.com/coturn/coturn/security/advisories/GHSA-6g6j-r9rf-cm7p"}, {"source": "security-advisories@github.com", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/coturn/coturn/security/advisories/GHSA-j8mm-mpf8-gvjg"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Not Applicable"], "url": "https://github.com/coturn/coturn/security/advisories/GHSA-6g6j-r9rf-cm7p"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/coturn/coturn/security/advisories/GHSA-j8mm-mpf8-gvjg"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-284"}, {"lang": "en", "value": "CWE-441"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,4.9.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "coturn", "source": "cna", "vendor": "coturn"}, "product": "coturn", "vendor": "coturn"}], "created": "2026-02-25T11:34:38.353504+00:00", "updated": "2026-02-25T11:34:38.353582+00:00", "vendors": ["coturn", "coturn$PRODUCT$coturn"]}