Craft CMS 5.0.0-RC1 before 5.10.12 Behavior Injection RCE
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-94.
Summary
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().
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA cms (craftcms) Fixed in 5.10.12
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
craftcms cms 5.10.12
3 records Highest priority Priority MEDIUM 2 MEDIUM, 1 LOW
Other records, highest priority first
- TI-2026-59289 Craft CMS before 5.10.12 Remote Code Execution via element-indexPriority MEDIUM 41
- TI-2026-59288 Craft CMS 5.0.0-RC1 before 5.10.12 Permission Escalation via UsersControllerPriority LOW 31
Timeline
- 2026-10-02 Threatist record created from CVE-2026-86730
- 2026-10-03 Alias added: GHSA-j4wp-xfvq-c8f7
References
More Craft CMS vulnerabilities
- TI-2025-23503 Craft CMS Allows Remote Code Execution KEVCVSS 3.1CRITICAL 10.0
- TI-2024-37138 RCE when PHP `register_argc_argv` config setting is enabled in craftcms/cms KEVCVSS 4.0CRITICAL 9.3
- TI-2025-16994 Potential RCE with a compromised security key in craft/cms KEVCVSS 3.1HIGH 8.1
- TI-2025-24595 Craft CMS stores user-provided content in session files KEVCVSS 4.0MEDIUM 6.9
- TI-2023-22284 Craft CMS Remote Code Execution vulnerability CVSS 3.1CRITICAL 10.0
- TI-2024-25171 Craft CMS up to v3.7.31 was discovered to contain a SQL injection vulnerability via the GraphQL API endpoint. CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-86730 · CVE Program
- CVE-2026-86730 · NVD
- FIRST EPSS
- GHSA-j4wp-xfvq-c8f7 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences