Link Following (Symlink)Weakness · CWE-59

CVE-2026-44711

HIGH · 7.9 CVSS v3.1 Published 2026-05-27
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
79/100
Remediation priority · High

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, symlink attacks on pad directory and pad files enable authentication bypass and root file corruption. This vulnerability is fixed in 0.8.7.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

pam_usb versions prior to 0.8.7 are vulnerable to symlink attacks on the pad directory and pad files. This allows attackers to bypass hardware authentication mechanisms and corrupt root-level files on the system.

MitigationUpgrade pam_usb to version 0.8.7 or later to address the symlink vulnerability. Review existing pad directory permissions and monitor for any unauthorized configuration changes.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
None
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check if pam_usb is installed
    Run 'dpkg -l | grep pam_usb' on Debian-based systems, or 'rpm -qa | grep pam_usb' on RHEL-based systems, or search for 'pam_usb' in the PAM modules directory (typically /lib/security/ or /lib64/security/)
    Affected if pam_usb is installed on the system
  2. Determine the installed pam_usb version
    Run 'dpkg -s pam_usb' or 'rpm -qi pam_usb' depending on your package manager, or check the module file version directly if installed from source
    Affected if the version returned is lower than 0.8.7 or cannot be determined (indicating an older build)
  3. Locate the pad directory configuration
    Check the pam_usb configuration file (typically /etc/pam_usb.conf or /etc/pam.d/pam_usb) and look for the 'pad' directive or 'device' settings that define the authentication storage location
    Affected if a pad directory is configured and points to a user-writable location
  4. Inspect pad directory and file permissions
    List the configured pad directory (e.g., 'ls -la /path/to/pad') and check for world-writable permissions or symlinks pointing to sensitive locations like /root or /etc
    Affected if the pad directory or its contents have weak permissions (world-writable) or contain suspicious symlinks to system directories
  5. Verify PAM configuration for pam_usb
    Check PAM configuration files in /etc/pam.d/ for entries referencing 'pam_usb' (e.g., 'grep -r pam_usb /etc/pam.d/')
    Affected if pam_usb is referenced in any PAM stack (common-auth, common-account, etc.), meaning it is actively used for authentication

The system is affected if pam_usb version 0.8.7 or higher is not installed AND pam_usb is configured in the PAM authentication stack with a pad directory that has weak permissions or symlink vulnerabilities.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade pam_usb to version 0.8.7 or later to address the symlink vulnerability. Review existing pad directory permissions and monitor for any unauthorized configuration changes.

Recommended fix Moderate confidence

0.8.7

  1. Upgrade pam_usb to version 0.8.7 or later
  2. Verify the upgrade using your distribution's package manager or compile from source from the official pam_usb repository
  3. After upgrading, verify that the pam_usb service is running correctly and authentication functions as expected

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-44711 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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