---
id: CVE-2026-92592
title: >-
  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
  bou…
summary: >-
  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
  bou…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-1336
vendor: craftcms
product: cms
affected:
  - cms >= 4.8.0 < 4.18.6
  - cms >= 5.0.0 < 5.10.13
published: '2026-09-16'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T20:25:55.870'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-92592'
references:
  - url: 'https://github.com/craftcms/cms/security/advisories/GHSA-5r92-75j8-c534'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/craft-cms-before-4.18.6-remote-code-execution-via-signed-cookie
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
epss: 0.00647
epssPercentile: 0.48818
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-17T18:57:22.910496Z'
ingestedAt: '2026-09-16T22:06:50.929Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.