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)
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.007 (52.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 52.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/craftcms/cms/security/advisories/GHSA-qj4v-m29p-fj4m (vendor-advisory)
- www.vulncheck.com/advisories/craft-cms-5.0.0-rc1-before-5.10.12-behavior-inject… (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.