{"id":"CVE-2026-48064","aliases":["EUVD-2026-32650","GHSA-w38v-cw9r-x9p6"],"status":"published","title":"pam_usb: PAM_RHOST check skipped when deny_remote=false allows XDMCP authentication bypass","description":"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.","severity":{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00342,"percentile":0.27981,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-863"],"published":"2026-05-27T19:59:53Z","modified":"2026-10-28T11:11:21Z","products":[{"vendor":"mcdope","product":"pam_usb"}],"references":[{"url":"https://github.com/mcdope/pam_usb/security/advisories/GHSA-w38v-cw9r-x9p6","tags":["x_refsource_CONFIRM","advisory"]},{"url":"https://github.com/mcdope/pam_usb/issues/348","tags":["x_refsource_MISC","exploit","report"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48064.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48064","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-48064","title":"pam_usb: PAM_RHOST check skipped when deny_remote=false allows XDMCP authentication bypass","description":"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.","status":"published","published":"2026-05-27T19:59:53.496Z","modified":"2026-06-02T17:40:46.535Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T13:50:49.872037Z"}],"euvd":[{"id":"EUVD-2026-32650","description":"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.","status":"published","published":"2026-05-27T19:59:53Z","modified":"2026-06-02T17:40:46Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T18:20:55.651138Z"}],"nvd":[{"id":"CVE-2026-48064","description":"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.","status":"published","published":"2026-05-27T20:16:40.23Z","modified":"2026-10-26T11:10:00.157Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T14:12:20.885865Z"}],"osv":[{"id":"CVE-2026-48064","title":"pam_usb: PAM_RHOST check skipped when deny_remote=false allows XDMCP authentication bypass","description":"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.","status":"published","published":"2026-05-27T19:59:53.496Z","modified":"2026-10-28T11:11:21.790223153Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T15:45:06.701612Z"}]}}