CVE-2026-62367

Vikunja: OIDC email-fallback account linking ignores email_verified, enabling local-account takeover

State: Published
Severity: 7.5 High
Published: Oct 9, 2026
Updated: Oct 13, 2026
Reserved: Jul 13, 2026

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.

Scores

CVSS	Score	Vector	Source
4.0	7.5 High	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	GitHub_M

Weaknesses

CWE-287 Improper Authentication
CWE-290 Authentication Bypass by Spoofing
CWE-345 Insufficient Verification of Data Authenticity

Affected Products

Product	Versions
vikunjago-vikunja	>= 1.0.0, < 2.4.0Affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.