# CVE-2026-33335: Vikunja Desktop allows arbitrary local application invocation via unvalidated shell.openExternal

> Attackers can trigger arbitrary local application execution or file access via unvalidated URLs in Vikunja Desktop, requiring a patch to secure external link handling.

- **Severity:** Medium 6.4 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 24 Mar 2026
- **Updated:** 25 Mar 2026
- **Also known as:** GHSA-6q44-85gc-cjvf

## What is CVE-2026-33335?

CVE-2026-33335 is a medium-severity vulnerability in go-vikunja vikunja, published on 24 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Vikunja is an open-source self-hosted task management platform. Starting in version 0.21.0 and prior to version 2.2.0, the Vikunja Desktop Electron wrapper passes URLs from `window.open()` calls directly to `shell.openExternal()` without any validation or protocol allowlisting. An attacker who can place a link with `target="_blank"` (or that otherwise triggers `window.open`) in user-generated content can cause the victim's operating system to open arbitrary URI schemes, invoking local applications, opening local files, or triggering custom protocol handlers. Version 2.2.0 patches the issue.

Weakness: CWE-939 (Improper Authorization in Handler for Custom URL Scheme)

## Which versions are affected by CVE-2026-33335?

It affects 1 product.


Products: Vikunja Vikunja.

## How do I fix CVE-2026-33335?

No fix has been published for CVE-2026-33335 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-33335 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33335 exists.

## Other vulnerabilities in go-vikunja vikunja

- [CVE-2026-28268](https://insights.sbomify.com/CVE-2026-28268/): Vikunja Vulnerable to Account Takeover via Password Reset Token Reuse (critical 9.8)
- [CVE-2026-27575](https://insights.sbomify.com/CVE-2026-27575/): Vijkunja has Weak Password Policy Combined with Persistent Sessions After Password Change (critical 9.1)
- [CVE-2026-25935](https://insights.sbomify.com/CVE-2026-25935/): Vikunja Affected by XSS Via Task Preview (high 8.6)
- [CVE-2026-35595](https://insights.sbomify.com/CVE-2026-35595/): Vikunja Affected by Privilege Escalation via Project Reparenting (high 8.3)
- [CVE-2026-33316](https://insights.sbomify.com/CVE-2026-33316/): Vikunja’s Improper Access Control Enables Bypass of Administrator-Imposed Account Disablement (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33335 and fix it if it is affected.

What it is: CVE-2026-33335 is a medium-severity vulnerability in go-vikunja vikunja, published on 24 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33335 exists.

Affected product: go-vikunja vikunja. 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-2026-33335/ (Markdown: https://insights.sbomify.com/CVE-2026-33335/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33335
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33335
- OSV: https://osv.dev/vulnerability/CVE-2026-33335

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-33335/
Summaries are generated and may contain mistakes; the official description above is the record.