CVE-2026-91983

Vikunja before 2.6.0 API Token Scope Bypass via expand Parameter

Published Sep 15, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-9rg3-v78m-26q8 Vikunja: API token scopes bypassed via task expand parameter (comments, reactions, time entry counts)
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title Vikunja before 2.6.0 API Token Scope Bypass via expand Parameter
First Time appeared Vikunja
Vikunja vikunja
Weaknesses CWE-863
CPEs cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*
Vendors & Products Vikunja
Vikunja vikunja
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 15, 2026, 3:52 PM
Reserved
Sep 15, 2026, 11:10 AM
Status
Deferred
Published
Sep 15, 2026, 4:17 PM
Modified
Sep 16, 2026, 8:16 PM