NULL Dereference Vulnerability in pam_usb Authentication Software by Linux Vendor

CVE-2026-48985

What is CVE-2026-48985?

The pam_usb module, which facilitates hardware authentication using removable media on Linux systems, is prone to a NULL dereference issue. This vulnerability arises from a flaw in the pusb_is_loginctl_local() function present in versions 0.9.1 and earlier. When parsing loginctl output, the function can fail and lead to a NULL pointer dereference if the Remote field consists solely of a newline. This situation causes the PAM module to crash, resulting in potential denial of service for all users relying on affected authentication processes (such as sudo and login). The problem has been resolved in version 0.9.2, and it's crucial for users to upgrade to ensure system integrity and maintain secure access control.

References