What is CVE-2026-86730?

CVE-2026-86730 is a high-severity vulnerability in Craftcms Cms, classified under Code Injection. CVSS score: 8.8/10. Published 2026-09-08.

How severe is CVE-2026-86730?

High severity. CVSS v3 base score is 8.8 out of 10.

RCE in Craftcms Cms

CVE-2026-86730

Craft CMS versions before 5.10.12 fail to properly cleanse string-typed field-layout elements, allowing authenticated control-panel users to inject Yii2 behavior attachments and event handlers. Attackers can post field-layout tab elements as JSON strings to bypass cleanse validation, then trigger arbitrary object instantiation and code execution through Craft::createObject().

Vulnerability class: RCE (Remote Code Execution)

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Craftcms Cms

Weakness classification (CWE)

CWE-94 — Code Injection

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-86730?: CVE-2026-86730 is a high-severity vulnerability in Craftcms Cms, classified under Code Injection. CVSS score: 8.8/10. Published 2026-09-08.
How severe is CVE-2026-86730?: High severity. CVSS v3 base score is 8.8 out of 10.