Cross-site Request Forgery (CSRF) Affecting concrete5/concrete5 package, versions <9.5.1
Threat Intelligence
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The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PHP-CONCRETE5CONCRETE5-17660479
- published27 Jun 2026
- disclosed21 May 2026
- creditUnknown
Introduced: 21 May 2026
CVE-2026-8426 (opens in a new tab)How to fix?
Upgrade concrete5/concrete5 to version 9.5.1 or higher.
Overview
concrete5/concrete5 is a concrete5 open source CMS.
Affected versions of this package are vulnerable to Cross-site Request Forgery (CSRF) via the /dashboard/extend/update/prepare_remote_upgrade/<remoteMPID> process. An attacker can execute arbitrary code as the web server user by tricking an authenticated user into visiting a crafted link, which triggers the upgrade process for a marketplace package controlled by the attacker. This is only exploitable if the victim site is connected to the Concrete marketplace, the attacker controls the package returned for a marketplace item ID already installed on the victim site, and the victim has the canInstallPackages permission.