CVE-2026-76216

Vikunja through 2.4.0 Principal-Type Confusion via LinkSharing

Published Aug 19, 2026 CVSS 4.0 · 7.7 High EPSS < 1% KEV · Not listed
Description
Vikunja through 2.4.0 contains a principal-type confusion vulnerability where LinkSharing principals with id N are treated as user principals with users.id == N at three permission checks lacking type guards. Attackers with a link-share JWT can remove victims from teams, enumerate and delete victim bot users, or read team rosters by exploiting id collisions in the autoincrement space.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-32r8-5843-4qw2 Vikunja: Link-share principal-type confusion enables cross-account team removal, bot takeover, and roster disclosure
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Vikunja through 2.4.0 contains a principal-type confusion vulnerability where LinkSharing principals with id N are treated as user principals with users.id == N at three permission checks lacking type guards. Attackers with a link-share JWT can remove victims from teams, enumerate and delete victim bot users, or read team rosters by exploiting id collisions in the autoincrement space.
Title Vikunja through 2.4.0 Principal-Type Confusion via LinkSharing
First Time appeared Vikunja
Vikunja vikunja
Weaknesses CWE-639
CPEs cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*
Vendors & Products Vikunja
Vikunja vikunja
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 7.7, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Aug 20, 2026, 4:10 PM
Reserved
Aug 19, 2026, 11:35 AM
Status
Deferred
Published
Aug 19, 2026, 2:17 PM
Modified
Sep 16, 2026, 8:18 PM