High severity · published Oct 12, 2026
CVE-2026-109308
Craft CMS 4.0.0 before 4.18.7 and 5.0.0 before 5.10.14 RCE via actionCacheUpdates Behavior Injection
8.8
CVSS
0.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 42% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CM
cms · craftcms
4.0.0 before 4.18.7; 5.0.0 before 5.10.14 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-109308
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-109308
vendor-advisory
https://github.com/craftcms/cms/security/advisories/GHSA-5m2g-hhqr-84pc
third-party-advisory
https://www.vulncheck.com/advisories/craft-cms-4.0.0-before-4.18.7-and-5.0.0-before-5.10.14-rce-via-actioncacheupdates-behavior-injection
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