CVE-2026-646667.1HighCWE-807

CVE-2026-64666: pam_usb: getenv() in pusb_local_login bypasses XRDP deny via env-var unset

mcdope · pam_usb

Affected: mcdope pam_usb · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.2%probability of exploitation in the next 30 days

7th percentile

050100

Higher than 7% of scored CVEs

7.1HighCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

mcdope · pam_usb< 0.9.3

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Reliance on Untrusted Inputs in a Security Decision · Input Validation and Logic
Vendor: mcdope
Published: November 2026
Band: Unlikely (under 1%), November 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-64666 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.