Description
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.
Published: 2026-10-09
Score: 7.5 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-xv7q-fvmc-jx96 Vikunja: OIDC email-fallback account linking ignores email_verified, enabling local-account takeover
History

Fri, 09 Oct 2026 22:45:00 +0000

Type Values Removed Values Added
First Time appeared Go-vikunja
Go-vikunja vikunja
Vendors & Products Go-vikunja
Go-vikunja vikunja

Fri, 09 Oct 2026 21:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Vikunja: OIDC email-fallback account linking ignores email_verified, enabling local-account takeover
Weaknesses CWE-287
CWE-290
CWE-345
References
Metrics cvssV4_0

{'score': 7.5, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


Subscriptions

Go-vikunja Vikunja
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-09T20:49:08.891Z

Reserved: 2026-07-13T22:04:59.677Z

Link: CVE-2026-62367

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-09T21:17:05.470

Modified: 2026-10-09T21:17:05.470

Link: CVE-2026-62367

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-09T22:30:13Z

Weaknesses
  • CWE-287

    Improper Authentication

  • CWE-290

    Authentication Bypass by Spoofing

  • CWE-345

    Insufficient Verification of Data Authenticity