Auth bypass in Go-Vikunja Vikunja
CVE-2026-33678
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.
Vulnerability class: IDOR (Insecure Direct Object Reference)
EPSS: 0.003 (18.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Go-vikunja Vikunja — versions < 2.2.1
- Vikunja
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-33678?
- CVE-2026-33678 is a high-severity vulnerability in Go-Vikunja Vikunja, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 8.1/10. Published 2026-03-24.
- How severe is CVE-2026-33678?
- High severity. CVSS v3 base score is 8.1 out of 10.