CVE-2026-54766: go-vikunja vikunja Improper Authorization

Vulnerability summary

CVE-2026-54766 is a medium (CVSS 5.3) Improper Authorization vulnerability in go-vikunja vikunja. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 35.9% of scored vulnerabilities.

Timeline

1. 28-08-2026
   PublishedVulnerability first disclosed.
2. 28-08-2026
   Last modifiedVulnerability information updated.

Description

Vikunja is an open-source self-hosted task management platform. From 0.21.0 until 2.4.0, the project duplication operation in pkg/models/project_duplicate.go allows an authenticated user who can read a source project to place its duplicate beneath an arbitrary target parent project. ProjectDuplicate.CanCreate calls parent.CanCreate on an unhydrated Project containing only the body supplied parent_project_id instead of calling parent.CanWrite, so the target parent write-permission check is skipped. The ordinary project creation path enforces that permission, but PUT /api/v1/projects/{project}/duplicate does not, allowing attacker-owned content to be injected into another user or team project hierarchy. This issue is fixed in version 2.4.0.

• CWE-285Improper AuthorizationThe product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
• CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.