What’s Vulnerable › Vulnerabilities

CVE-2026-33678: Vikunja has IDOR in Task Attachment ReadOne Allows Cross-Project File Access and Deletion

• Severity: high (CVSS 8.1 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-639

Description

Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.1, `TaskAttachment.ReadOne()` queries attachments by ID only (`WHERE id = ?`), ignoring the task ID from the URL path. The permission check in `CanRead()` validates access to the task specified in the URL, but `ReadOne()` loads a different attachment that may belong to a task in another project. This allows any authenticated user to download or delete any attachment in the system by providing their own accessible task ID with a target attachment ID. Attachment IDs are sequential integers, making enumeration trivial. Version 2.2.1 patches the issue.

Affected products

• go-vikunja vikunja: before 2.2.1 — fixed in 2.2.1

How to fix

Upgrade to a fixed version: go-vikunja vikunja 2.2.1. Check the vendor advisory for mitigations.

References

• https://github.com/go-vikunja/vikunja/security/advisories/GHSA-jfmm-mjcp-8wq2
• https://vikunja.io/changelog/vikunja-v2.2.2-was-released

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