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[ CVE-2026-91985 · Published 15 Sep 2026 ]

Vikunja: Read-only project members can obtain any link share's access hash via the single-share read endpoint (v1 and v2) and escalate to the share's permission level

CVSS 7.5 EPSS <1%Fix available

[ Why it matters ]Priority signals

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

[ Description ]Official description

Vikunja before 2.6.0 fails to properly restrict access to the link-share hash field in single-share read endpoints, allowing read-only members to obtain the share's secret credential. Attackers can exchange the disclosed hash for a link-share JWT at the share's permission level to escalate privileges and perform unauthorized writes or administrative actions.

[ 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