# CVE-2026-31893: Tunnelblick arbitrary file read via symlink following in tunnelblickd

> Local attackers can read arbitrary root-owned files via symlink following in Tunnelblick's helper process due to missing authorization and symlink validation.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 May 2026
- **Updated:** 5 May 2026
- **Also known as:** GHSA-927j-vcjf-hq69

## What is CVE-2026-31893?

CVE-2026-31893 is a medium-severity path traversal vulnerability in Tunnelblick, published on 5 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

Weakness: CWE-61 (UNIX Symbolic Link (Symlink) Following)

## Which versions are affected by CVE-2026-31893?

It affects 1 product.


Products: Tunnelblick Tunnelblick.

## How do I fix CVE-2026-31893?

No fix has been published for CVE-2026-31893 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-31893 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31893 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-31893 and fix it if it is affected.

What it is: CVE-2026-31893 is a medium-severity path traversal vulnerability in Tunnelblick, published on 5 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31893 exists.

Affected product: Tunnelblick. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-31893/ (Markdown: https://insights.sbomify.com/CVE-2026-31893/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31893
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31893
- OSV: https://osv.dev/vulnerability/CVE-2026-31893

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31893/
Summaries are generated and may contain mistakes; the official description above is the record.