Vulnerability · Published Oct 12, 2026 · Assigned by VulnCheck

CVE-2026-109308Craft CMS 4.0.0 before 4.18.7 and 5.0.0 before 5.10.14 RCE via actionCacheUpdates Behavior Injection

High 8.8

In plain English

A high-severity code injection in cms from craftcms. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities).

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.5%top 57.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Craft CMS 4.0.0 before 4.18.7 and 5.0.0 before 5.10.14 passes the raw 'updates' request parameter in AppController::actionCacheUpdates to UpdatesModel without Component::cleanseConfig(), allowing behavior and event-handler injection. Authenticated control panel users with the performUpdates permission or Updates-utility access can supply 'as' or 'on' keys, such as an AttributeTypecastBehavior gadget, to execute arbitrary code.

Affected products (as reported)

Vendor	Product	Versions
craftcms	cms	4.0.0 – before 4.18.7
craftcms	cms	5.0.0 – before 5.10.14

Weakness: CWE-94 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

GitHub Security Advisory (GHSA-5m2g-hhqr-84pc) vendor-advisory
VulnCheck Advisory: Craft CMS 4.0.0 before 4.18.7 and 5.0.0 before 5.10.14 RCE via actionCacheUpdates Behavior Injection third-party-advisory