CVE-2026-91983

Vikunja before 2.6.0 contains an API token scope bypass vulnerability in task read endpoints where authorization fails to inspect query string parameters. Attackers with limited token scopes can use the expand parameter to access restricted data like comments, reactions, and time entries without proper permission verification.

  • Published Sep 15, 2026
  • CVSS 5.3 medium
  • 0.3% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-91983 at the National Vulnerability Database