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

Severity: high (CVSS 8.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-03-24 · updated 2026-06-17
Weakness: CWE-939

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.

Affected products

go-vikunja vikunja: from 0.21.0 before 2.2.2 — fixed in 2.2.2

How to fix

Upgrade to a fixed version: go-vikunja vikunja 2.2.2. Check the vendor advisory for mitigations.

References

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