CVE-2026-48064
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.34%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 8.1 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.34% probability · 27th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-863
- Source
- security-advisories@github.com
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.