CVE-2026-48986
CWE-835Published: June 18, 2026· Updated: Jun 22, 2026
Official Description
pam_usb provides hardware authentication for Linux using removable media. In pam_usb 0.9.1 and earlier, usb_get_process_parent_id() can cause an infinite loop DoS because it does not initialize *ppid on failure. In pusb_local_login(), the same variable is reused as input and output in a process-tree while loop; if /proc/<pid>/stat cannot be read (for example, when an ancestor process exits during authentication), the PID is not updated and the loop does not terminate. This hangs the authenticating process (such as sudo, sshd, or login) until it is forcibly terminated. This issue has been fixed in version 0.9.2.
Technical Analysis
CVE-2026-48986 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 4.7.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
All References (2)
Quick Facts
Related CVEs (CWE-835)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-48986 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts