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

8.7 High

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.49%Unchanged since Oct 13, 2026

What each source reports

CVE List Score used 8.7

Craft CMS 4.0.0 before 4.18.7 and 5.0.0 before 5.10.14 RCE via actionCacheUpdates Behavior Injection

Record: CVE-2026-109308
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-94
Updated: 2026-11-02

EUVDEUVD-2026-97610 8.7

Record: EUVD-2026-97610
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-r8mr-vm79-xxh4 8.7

Craft CMS 4.0.0 before 4.18.7 and 5.0.0 before 5.10.14 passes the raw 'updates' request parameter...

Record: GHSA-r8mr-vm79-xxh4
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-94
Updated: 2026-11-02

NVD 8.7

Record: CVE-2026-109308
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-94
Updated: 2026-11-02

OSV 8.7

Craft CMS 4.0.0 before 4.18.7 and 5.0.0 before 5.10.14 RCE via actionCacheUpdates Behavior Injection

Record: CVE-2026-109308
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Weakness: CWE-94
Updated: 2026-11-02

Affected products

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-109308 is a high vulnerability (CVSS 8.7) in Craftcms Cms, published October 12, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.49%, the 42nd percentile. No source names a fixed version.