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TI-2026-34854 Aliases CVE-2026-47274

pam_usb: Uncontrolled search path in pam_usb tools allows privilege escalation via PATH manipulation

Priority LOW 29CWE-427Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
Code execution
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-427.

Summary

pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, multiple pam_usb helper tools resolved external binaries through the PATH environment variable rather than using absolute paths. An attacker who can influence the process environment during PAM authentication or tool execution could substitute malicious binaries. The affected tools are pamusb-check (src/tmux.c), pamusb-conf (tools/pamusb-conf), and pamusb-keyring-unlock-gnome (tools/pamusb-keyring-unlock-gnome). This vulnerability is fixed in 0.9.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00141 3rd percentileScored 2026-11-07
Fix Fixed pam_usb (mcdope): 0.9.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
mcdopepam_usbbefore 0.9.00.9.0Patch availableCNA
  • pam_usb Vendormcdope Affected before 0.9.0 Fixed in 0.9.0 Patch available CNA

Remediation

  • Fix · CNA pam_usb (mcdope) Fixed in 0.9.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-47274

References

Other 4

  • TI-2026-35505 pam_usb: PAM_RHOST check skipped when deny_remote=false allows XDMCP authentication bypass CVSS 3.1HIGH 8.1
  • TI-2026-32598 pam_usb: Symlink attacks on pad directory and pad files enable authentication bypass and root file corruption CVSS 3.1HIGH 7.9
  • TI-2026-32596 pam_usb: PINENTRY_FALLBACK_APP environment variable allows arbitrary command execution CVSS 3.1HIGH 7.8
  • TI-2026-32600 pam_usb: Command injection via $TMUX environment variable leads to RCE as root CVSS 3.1HIGH 8.8
  • TI-2026-32599 pam_usb: Shell injection via device UUID and username in pamusb-conf and pamusb-agent CVSS 3.1HIGH 8.2
  • TI-2026-34849 pam_usb: deny_remote feature incorrectly classifies IPv4-mapped IPv6 remote connections as local CVSS 3.1HIGH 7.4
See all 21 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences