CVE-2026-62367
Vikunja: OIDC email-fallback account linking ignores email_verified, enabling local-account takeover
Impact
Vikunja is an open-source self-hosted task management platform. In versions 1.0.0 through 2.3.0, when an administrator enables the per-provider `emailfallback` option on an OpenID Connect provider, Vikunja links an SSO login to a pre-existing local (username+password) account using only the `email` claim from the IdP. The fallback never checks an `email_verified` (or Microsoft `xms_edov`) signal and never requires the matched account's password. An attacker who can obtain a token from the configured issuer carrying a victim's email logs in as that victim with a full session, with no consent or interaction from the victim. Version 2.4.0 fixes the issue.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | code.vikunja.io/api | >= 1.0.0, <= 2.3.0 | 2.4.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-xv7q-fvmc-jx96
- https://github.com/go-vikunja/vikunja/security/advisories/GHSA-xv7q-fvmc-jx96
- https://github.com/go-vikunja/vikunja/commit/7854f2729ab72000210b61c25929678fd6901630
- https://github.com/go-vikunja/vikunja/releases/tag/v2.4.0