CVE-2026-27624

{"id": "CVE-2026-27624", "cveTags": [], "metrics": {"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}]}, "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 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."}], "lastModified": "2026-02-27T18:04:29.457", "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"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}