Vikunja: API token scopes bypassed via task expand parameter (comments, reactions, time entry counts) — GHSA-9RG3-V78M-26Q8

Summary

## Summary API token permission checks only match the HTTP method and route path. The `expand` query parameter on task read endpoints embeds data from other permission groups (task comments, reactions, time entry counts) without checking whether the token holds those scopes. A token scoped only to `tasks` read permissions can therefore read task comments and reactions it was explicitly not granted. ## Details…

Timeline

Published by source

2026-10-09

Risk context

• Reported severity or threat level: medium.
• Reported CVSS score: 5.3 out of 10.
• Reported EPSS value: 0.00305.
• Review exposure for the affected product or family: go: code.vikunja.io/api.

Product

go: code.vikunja.io/api

What to do

General, cautious steps (verify details in the official source):

• Review exposure and plan remediation based on risk and environment.
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-9RG3-V78M-26Q8

Source

GitHub

Vendor

GitHub

Published by source

2026-10-09

Last source activity

2026-10-09

Additional identifiers

CVE-2026-91983

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.