cyfenced.com →

[ CVE-2026-91981 · Published 15 Sep 2026 ]

Vikunja: Link-share token can enumerate users through the v2 API

CVSS 4.3 EPSS <1%Fix available

[ Why it matters ]Priority signals

  • Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

Vikunja versions before 2.6.0 fail to properly validate link-share tokens in the v2 API user search endpoints. Attackers with a read-only share link can enumerate project users via the projects endpoint and confirm arbitrary usernames exist via the global search endpoint.

[ Fixes ]Fixes and patches

  • code.vikunja.io/api 2.6.0Fixed version · GitHub Advisories · go package code.vikunja.io/api: upgrade to 2.6.0 or later (affected <= 2.5.0)

[ Packages ]Affected open-source packages

[ References ]References