CVE-2026-92592
High CVSS 8.8Published 2026-09-16 ยท last changed 2026-09-17
The fix
We hold no Microsoft remediation data for CVE-2026-92592, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.
What it is
Craft CMS 4.8.0 through 4.18.5 and 5.0.0 through 5.10.12 sign an authenticated user's attacker-controlled license-shun cookie with the same key and format used to validate signed redirect parameters, because the HMAC signature is not bound to its purpose (Yii's cookieValidationKey is derived from the same Craft securityKey used for signed request parameters). An authenticated, non-administrator user (Control Panel access is not required) can set the cookie via the license-shun endpoint and transplant the signed envelope into the redirect parameter; on a successful login, Craft validates the signature and renders the authenticated bytes as an unsandboxed Twig template, where Twig's map filter accepts a string callback and allows PHP system() to execute arbitrary operating-system commands as the web-server user. Exploitation requires an account using password authentication without active 2FA, the default request configuration, and availability of PHP system(). The issue is fixed in 4.18.6 and 5.10.13.
Sources
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H