{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-47269", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-05-18T23:03:37.229Z", "datePublished": "2026-05-27T20:11:44.975Z", "dateUpdated": "2026-05-27T20:11:44.975Z"}, "containers": {"cna": {"title": "pam_usb: deny_remote feature incorrectly classifies IPv4-mapped IPv6 remote connections as local", "problemTypes": [{"descriptions": [{"cweId": "CWE-284", "lang": "en", "description": "CWE-284: Improper Access Control", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.4, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/mcdope/pam_usb/security/advisories/GHSA-jmmj-qhrq-w45g", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/mcdope/pam_usb/security/advisories/GHSA-jmmj-qhrq-w45g"}, {"name": "https://github.com/mcdope/pam_usb/commit/804fe24eae3d742d8be05fd015e36abc3c7d94e5", "tags": ["x_refsource_MISC"], "url": "https://github.com/mcdope/pam_usb/commit/804fe24eae3d742d8be05fd015e36abc3c7d94e5"}], "affected": [{"vendor": "mcdope", "product": "pam_usb", "versions": [{"version": "< 0.9.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-05-27T20:11:44.975Z"}, "descriptions": [{"lang": "en", "value": "pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, pam_usb's deny_remote feature checks utmpx ut_addr_v6 to detect whether an authentication request originates from a remote session. The outer guard was if (utent->ut_addr_v6[0] != 0), which only tests the first 32-bit word of the 128-bit address field. IPv4-mapped IPv6 addresses (::ffff:x.x.x.x) store the IPv4 address in ut_addr_v6[3] with ut_addr_v6[0] == 0. On systems where the SSH daemon listens on :: (IPv6 wildcard) with AddressFamily any -- common on Ubuntu and Debian -- incoming IPv4 connections are recorded in utmpx as IPv4-mapped IPv6 addresses. The outer check evaluates to false, the remote-detection block is skipped entirely, and the session is treated as local. deny_remote=true does not block the authentication. An attacker with physical access to a registered USB device can authenticate over SSH on an affected system as if they were sitting at a local terminal, bypassing the deny_remote restriction. This vulnerability is fixed in 0.9.0."}], "source": {"advisory": "GHSA-jmmj-qhrq-w45g", "discovery": "UNKNOWN"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, pam_usb's deny_remote feature checks utmpx ut_addr_v6 to detect whether an authentication request originates from a remote session. The outer guard was if (utent->ut_addr_v6[0] != 0), which only tests the first 32-bit word of the 128-bit address field. IPv4-mapped IPv6 addresses (::ffff:x.x.x.x) store the IPv4 address in ut_addr_v6[3] with ut_addr_v6[0] == 0. On systems where the SSH daemon listens on :: (IPv6 wildcard) with AddressFamily any -- common on Ubuntu and Debian -- incoming IPv4 connections are recorded in utmpx as IPv4-mapped IPv6 addresses. The outer check evaluates to false, the remote-detection block is skipped entirely, and the session is treated as local. deny_remote=true does not block the authentication. An attacker with physical access to a registered USB device can authenticate over SSH on an affected system as if they were sitting at a local terminal, bypassing the deny_remote restriction. This vulnerability is fixed in 0.9.0."}], "id": "CVE-2026-47269", "lastModified": "2026-05-27T21:16:18.810", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.4, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 5.2, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-05-27T21:16:18.810", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/mcdope/pam_usb/commit/804fe24eae3d742d8be05fd015e36abc3c7d94e5"}, {"source": "security-advisories@github.com", "url": "https://github.com/mcdope/pam_usb/security/advisories/GHSA-jmmj-qhrq-w45g"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-284"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"created": "2026-05-27T22:30:35.626650+00:00", "updated": "2026-05-27T22:30:35.626659+00:00", "vendors": []}