{"id":"CVE-2026-48064","summary":"pam_usb: PAM_RHOST check skipped when deny_remote=false allows XDMCP authentication bypass","details":"pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.1, when a PAM service is configured with deny_remote=false in pam_usb (commonly done for display managers such as gdm-password or lightdm to bypass process/TTY heuristics for local sessions), the PAM_RHOST check in pusb_do_auth() is also skipped. PAM_RHOST is set by remote daemons (sshd, XDMCP servers) to identify the remote client address. Because the check is gated inside if (opts.deny_remote), a genuine remote XDMCP connection reaches the USB device authentication step instead of being rejected. This vulnerability is fixed in 0.9.1.","aliases":["GHSA-w38v-cw9r-x9p6"],"modified":"2026-07-15T23:39:34.634583Z","published":"2026-05-27T19:59:53.496Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-863"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48064.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48064.json"},{"type":"ADVISORY","url":"https://github.com/mcdope/pam_usb/security/advisories/GHSA-w38v-cw9r-x9p6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48064"},{"type":"REPORT","url":"https://github.com/mcdope/pam_usb/issues/348"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mcdope/pam_usb","events":[{"introduced":"0"},{"fixed":"e2f30b22cd0715fcde0fc62d6ee3e1ca6370b8a9"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"0.9.1"}],"source":"AFFECTED_FIELD"}}],"versions":["0.9.0","0.8.7","0.8.4","0.8.3","v0.8.0","0.7.3","0.7.2","0.7.1","v0.7.0","0.5.0"],"database_specific":{"vanir_signatures_modified":"2026-07-15T23:39:34Z","vanir_signatures":[{"deprecated":false,"digest":{"line_hashes":["32897324108646938673138056869665931337"],"threshold":0.9},"id":"CVE-2026-48064-b792a2ae","signature_type":"Line","signature_version":"v1","source":"https://github.com/mcdope/pam_usb/commit/e2f30b22cd0715fcde0fc62d6ee3e1ca6370b8a9","target":{"file":"src/version.h"}}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48064.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}