Vikunja: OIDC email-fallback account linking ignores email_verified, enabling local-account takeover — GHSA-XV7Q-FVMC-JX96

Summary

## Summary With the per-provider OIDC `emailfallback` option enabled, Vikunja links an SSO login to a pre-existing **local** (username+password) account using only the `email` claim — no `email_verified` (or Microsoft `xms_edov`) check and no password check, on the unauthenticated callback. An attacker who can make the configured issuer emit a token bearing a victim's email logs in as that victim with a full…

Timeline

Published by source

2026-10-09

Risk context

• Reported severity or threat level: high.
• Reported CVSS score: 7.5 out of 10.
• 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):

• Prioritize patching or mitigation immediately (treat as actively risky).
• 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-XV7Q-FVMC-JX96

Source

GitHub

Vendor

GitHub

Published by source

2026-10-09

Last source activity

2026-10-09

Additional identifiers

CVE-2026-62367

Curated by

hlukh.ch

Related advisories and connections

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