What is CVE-2026-91983?

CVE-2026-91983 is a medium-severity vulnerability in Go-Vikunja Vikunja, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2026-09-15.

How severe is CVE-2026-91983?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Auth bypass in Go-Vikunja Vikunja

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.

Vulnerability class: Broken Access Control

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

Affected products

Go-vikunja Vikunja

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-91983?: CVE-2026-91983 is a medium-severity vulnerability in Go-Vikunja Vikunja, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2026-09-15.
How severe is CVE-2026-91983?: Medium severity. CVSS v3 base score is 4.3 out of 10.