Craft CMS's race condition in Token Service potentially allows for token usage greater than the token limit

Summary

Craft is a content management system (CMS). In versions 4.5.0-RC1 through 4.16.18 and 5.0.0-RC1 through 5.8.22, a Time-of-Check-Time-of-Use (TOCTOU) race condition exists in Craft CMS’s token validation service for tokens that explicitly set a limited usage. The `getTokenRoute()` method reads a token’s usage count, checks if it’s within limits, then updates the database in separate non-atomic operations. By sending concurrent requests, an attacker can use a single-use impersonation token multiple times before the database update completes. To make this work, an attacker needs to obtain a valid user account impersonation URL with a non-expired token via some other means and exploit a race condition while bypassing any rate-limiting rules in place. For this to be a privilege escalation, the impersonation URL must include a token for a user account with more permissions than the current user. Versions 4.16.19 and 5.8.23 patch the issue.

Timeline

1. Feb 24, 2026, 2:42 AM UTCCVE published
2. Feb 28, 2026, 2:13 AM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. Feb 28, 2026, 2:13 AM UTCRecord last updated

Affected versions

• craftcms cms

  From 4.5.0-RC1 · fixed in 4.16.19; From 5.0.0-RC1 · fixed in 5.8.23

• craftcms/cmsPackagist

  From 4.5.0-RC1 · fixed in 4.16.19

• craftcms/cmsPackagist

  From 5.0.0-RC1 · fixed in 5.8.23

References 2