# CVE-2026-62367: Vikunja OIDC email-fallback account linking ignores email_verified

Source: https://junglewise.ai/threats/cve-2026-62367-vikunja-oidc-email-fallback-account-linking-ignores-email  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-09. Updated: 2026-10-09  
License: CC BY 4.0 with a link back

CVE-2026-62367 · Severity: high · CVSS 4 · Published 2026-10-09

Vikunja is a task and project management application that supports single sign-on (SSO) authentication. When the OIDC email-fallback feature is enabled, an attacker who controls an SSO provider can claim any user's email address and automatically log in as that user's local account without needing their password. This grants complete access to read, modify, and delete all projects, tasks, and data belonging to that account.

Technologies: [code.vikunja.io/api (Go)](https://junglewise.ai/threats/technologies/code-vikunja-io-api), [Vikunja](https://junglewise.ai/threats/technologies/vikunja). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Vikunja](https://junglewise.ai/threats/vendors/vikunja).

## Quick answers

**Is CVE-2026-62367 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-62367 being exploited in the wild.

**How severe is CVE-2026-62367?** High severity, with a CVSS score of 4, published 9 October 2026.

**Which products and versions are affected?** code.vikunja.io/api (Go) >= 1.0.0, <= 2.3.0, SEMVER:introduced=0, SEMVER:introduced=1.0.0,fixed=2.4.0; Vikunja before 2.3.1.

**Is there a fix for CVE-2026-62367?** Yes. code.vikunja.io/api (Go): upgrade to 2.4.0 or later. Until then: Disable the OIDC emailfallback option (set emailfallback: false in per-provider configuration) until upgrading. If emailfallback must remain enabled, restrict which identity providers are configured to only single-tenant, email-verifying issuers that prevent users from setting unverified email addresses. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-62367 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-62367?** Check whether you run code.vikunja.io/api (Go) or Vikunja at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- code.vikunja.io/api (Go): upgrade to 2.4.0 or later

  ```sh
  go get code.vikunja.io/api@v2.4.0
  ```


Disable the OIDC emailfallback option (set emailfallback: false in per-provider configuration) until upgrading. If emailfallback must remain enabled, restrict which identity providers are configured to only single-tenant, email-verifying issuers that prevent users from setting unverified email addresses.

## Technical details

The vulnerability exists in the OIDC authentication module's email-fallback functionality, which links SSO logins to local accounts using only the email claim without verifying that the email address was actually confirmed by the identity provider. The vulnerable code in openid.go performs a database lookup matching issuer='local' and email claim, then creates an authenticated session without checking email_verified or requiring a password. Users with TOTP enabled are protected by a separate gate added in version 2.3.0, but non-TOTP users remain vulnerable.

## Affected products

- Vikunja Vikunja before 2.3.1

## Identifiers

- CVE-2026-62367
- GHSA-xv7q-fvmc-jx96
- GO-2026-6758

## Timeline

- 2026-10-09: disclosed

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