CVE-2026-33680: Vikunja Vulnerable to Link Share Hash Disclosure via ReadAll Endpoint Enables Permission Escalation

Vulnerability summary

CVE-2026-33680 is a high (CVSS 7.5) Improper Authorization vulnerability in go-vikunja vikunja. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 40.3% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 24-03-2026
   PublishedVulnerability first disclosed.
2. 26-03-2026
   Last modifiedVulnerability information updated.

Description

Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.2, the `LinkSharing.ReadAll()` method allows link share authenticated users to list all link shares for a project, including their secret hashes. While `LinkSharing.CanRead()` correctly blocks link share users from reading individual shares via `ReadOne`, the `ReadAllWeb` handler bypasses this check by never calling `CanRead()`. An attacker with a read-only link share can retrieve hashes for write or admin link shares on the same project and authenticate with them, escalating to full admin access. Version 2.2.2 patches the issue.

• 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.