{"api_version":"1","generated_at":"2026-05-28T16:29:41+00:00","cve":"CVE-2026-47269","urls":{"html":"https://cve.report/CVE-2026-47269","api":"https://cve.report/api/cve/CVE-2026-47269.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-47269","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-47269"},"summary":{"title":"pam_usb: deny_remote feature incorrectly classifies IPv4-mapped IPv6 remote connections as local","description":"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.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-05-27 21:16:18","updated_at":"2026-05-28 13:57:25"},"problem_types":["CWE-284","CWE-284 CWE-284: Improper Access Control"],"metrics":[{"version":"3.1","source":"security-advisories@github.com","type":"Secondary","score":"7.4","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","baseScore":7.4,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.4","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","data":{"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":[{"url":"https://github.com/mcdope/pam_usb/security/advisories/GHSA-jmmj-qhrq-w45g","name":"https://github.com/mcdope/pam_usb/security/advisories/GHSA-jmmj-qhrq-w45g","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/mcdope/pam_usb/commit/804fe24eae3d742d8be05fd015e36abc3c7d94e5","name":"https://github.com/mcdope/pam_usb/commit/804fe24eae3d742d8be05fd015e36abc3c7d94e5","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-47269","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-47269","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"mcdope","product":"pam_usb","version":"affected < 0.9.0","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-47269","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","timestamp":"2026-05-28T12:50:16.970323Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-05-28T12:50:50.859Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"product":"pam_usb","vendor":"mcdope","versions":[{"status":"affected","version":"< 0.9.0"}]}],"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."}],"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-284","description":"CWE-284: Improper Access Control","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-05-27T20:11:44.975Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"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"}],"source":{"advisory":"GHSA-jmmj-qhrq-w45g","discovery":"UNKNOWN"},"title":"pam_usb: deny_remote feature incorrectly classifies IPv4-mapped IPv6 remote connections as local"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-47269","datePublished":"2026-05-27T20:11:44.975Z","dateReserved":"2026-05-18T23:03:37.229Z","dateUpdated":"2026-05-28T12:50:50.859Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-27 21:16:18","lastModifiedDate":"2026-05-28 13:57:25","problem_types":["CWE-284","CWE-284 CWE-284: Improper Access Control"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","baseScore":7.4,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE"},"exploitabilityScore":2.2,"impactScore":5.2}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"47269","Ordinal":"1","Title":"pam_usb: deny_remote feature incorrectly classifies IPv4-mapped ","CVE":"CVE-2026-47269","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"47269","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"pam_usb: deny_remote feature incorrectly classifies IPv4-mapped "}]}}}