Vulnerability Description
Tunnelblick is an open source graphic user interface for OpenVPN on macOS. In versions 3.3beta26 through 9.0beta01, any local user can read arbitrary root-owned files by exploiting a symlink following vulnerability in tunnelblick-helper, reachable through the world-accessible tunnelblickd Unix socket. The socket is configured with mode 0666, allowing any local user to connect. No authorization check is performed on the connecting client. The tunnelblick-helper process constructs a path to config.ovpn inside a user-controlled .tblk directory and reads it as root without symlink validation. An attacker can create a .tblk configuration with a symlinked config.ovpn pointing to any file and request tunnelblickd to read it. This issue has been fixed in versions 9.0beta02.
Related Weaknesses (CWE)
References
- https://github.com/Tunnelblick/Tunnelblick/releases/tag/v9.0beta02
- https://github.com/Tunnelblick/Tunnelblick/security/advisories/GHSA-927j-vcjf-hq
- https://github.com/Tunnelblick/Tunnelblick/security/advisories/GHSA-927j-vcjf-hq
FAQ
What is CVE-2026-31893?
CVE-2026-31893 is a documented vulnerability. Tunnelblick is an open source graphic user interface for OpenVPN on macOS. In versions 3.3beta26 through 9.0beta01, any local user can read arbitrary root-owned files by exploiting a symlink following...
How severe is CVE-2026-31893?
CVSS scoring is not yet available for CVE-2026-31893. Check NVD for updates.
Is there a patch for CVE-2026-31893?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.