Answer in brief
CVE-2026-64666 records a High severity (CVSS 7.1) vulnerability in pam_usb: getenv() in pusb_local_login bypasses XRDP deny via env-var unset. The current sources do not mark it as known exploited. The current feed maps mcdope/pam_usb (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps mcdope/pam_usb (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| mcdope/pam_usbgeneric | <0.9.3 | 0.9.3 |
Published upstream
Nov 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 11, 2026
pam_usb provides hardware authentication for Linux using removable media. Prior to version 0.9.3, src/local.c reads XRDP_SESSION with plain getenv(3) at the head of pusb_local_login while every other env consumer in the same function uses secure_getenv(3). When pam_usb.so loads into a setuid PAM host, the calling user controls the environment passed in. Clearing XRDP_SESSION before invoking the host bypasses the explicit XRDP-deny rule. Other remote-detection signals (rmsvc, evdev, loginctl, utmp) may still catch the session, but the env-based detection alone is defeated. This issue has been patched in version 0.9.3.
Quoted source text, attributed separately from HOL analysis.