CVE-2026-44713: high-severity vulnerability in mcdope pam_usb
pam_usb: Command injection via $TMUX environment variable leads to RCE as root
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.8epss 0.2%
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, src/tmux.c reads the user's $TMUX environment variable, splits it on commas, and interpolates the socket-path component directly into a shell command passed to popen(). Because the value is placed inside double-quotes without sanitisation, any value containing " terminates the quoted string and injects arbitrary shell syntax. popen() runs as root inside the PAM stack. This vulnerability is fixed in 0.8.7.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Affected products
mcdope · pam_usbRelated CVEs — mcdope pam_usb
In the same product, most dangerous first.
CVE-2026-64669HIGHpam_usb: deny_remote bypassed by compressed IPv6 addresses in pusb_tmux_has_remote_clientsEPSS 0.4%CVE-2026-64668HIGHpam_usb: deny_remote bypassed by zone-indexed IPv6 addresses (fe80::1%eth0) in pusb_tmux_has_remote_clientsEPSS 0.4%CVE-2026-48064HIGHpam_usb: PAM_RHOST check skipped when deny_remote=false allows XDMCP authentication bypassEPSS 0.3%CVE-2026-47269HIGHpam_usb: deny_remote feature incorrectly classifies IPv4-mapped IPv6 remote connections as localEPSS 0.3%CVE-2026-47273MEDIUMpam_usb: XPath injection via PAM-supplied identifiers in pam_usb configuration queriesEPSS 0.3%CVE-2026-44711HIGHpam_usb: Symlink attacks on pad directory and pad files enable authentication bypass and root file corruptionEPSS 0.2%