CVE-2026-31893

Tunnelblick arbitrary file read via symlink following in tunnelblickd

MEDIUM
5.5
CVSS Score
Published: May 5, 2026 at 06:55 PM UTC
Updated: July 25, 2026 at 11:21 AM UTC
1 product affected across 1 vendorTunnelblick

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Affected range stops below 8.0.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 9.0beta02, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

x_refsource_CONFIRMExploitVendor Advisory
Source: cverecord
https://github.com/Tunnelblick/Tunnelblick/security/advisories/GHSA-927j-vcjf-hq69
x_refsource_MISCProductRelease Notes
Source: cverecord
https://github.com/Tunnelblick/Tunnelblick/releases/tag/v9.0beta02

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-61

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