Answer in brief
CVE-2026-86730 records a High severity (CVSS 8.8) vulnerability in Craft CMS 5.0.0-RC1 before 5.10.12 Behavior Injection RCE. The current sources do not mark it as known exploited. The current feed maps craftcms/cms (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps craftcms/cms (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| craftcms/cmsgeneric | >=5.0.0-RC1 <5.10.12 | 5.10.12 |
Published upstream
Sep 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 8, 2026
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().
Quoted source text, attributed separately from HOL analysis.