{"id":"CVE-2026-27128","aliases":["GHSA-6fx5-5cw5-4897"],"url":"https://o3.security/vulnerability/CVE-2026-27128","summary":"Craft CMS's race condition in Token Service potentially allows for token usage greater than the token limit","details":"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.","published":"2026-02-24T02:42:53.706Z","modified":"2026-08-12T03:51:37.035524372Z","cvss":null,"epss":{"score":0.00176,"percentile":0.07138,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"craftcms/cms","fixedVersion":"4.16.19"},{"ecosystem":"Packagist","name":"craftcms/cms","fixedVersion":"5.8.23"}],"fix":{"url":"https://github.com/craftcms/cms/commit/3e4afe18279951c024c64896aa2b93cda6d95fdf","label":"craftcms/cms@3e4afe1"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27128.json"},{"type":"ADVISORY","url":"https://github.com/craftcms/cms/security/advisories/GHSA-6fx5-5cw5-4897"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27128"},{"type":"FIX","url":"https://github.com/craftcms/cms/commit/3e4afe18279951c024c64896aa2b93cda6d95fdf"},{"type":"PACKAGE","url":"https://github.com/craftcms/cms"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:37.035524372Z"}}