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PatchSiren cyber security CVE debrief

CVE-2026-56382 craftcms CVE debrief

CVE-2026-56382 is a high-severity remote code execution vulnerability in Craft CMS versions >= 5.5.0 and <= 5.9.13. The vulnerability exists in the FieldsController::actionRenderCardPreview() method, which passes the fieldLayoutConfig POST parameter directly to Fields::createLayout() without proper sanitization. An authenticated admin user can inject Yii2 event handlers to execute arbitrary PHP code and disclose sensitive information. The issue is fixed in version 5.9.14. Defenders should prioritize patching due to the high CVSS score of 8.6 and the potential for significant impact.

Vendor
craftcms
Product
cms
CVSS
HIGH 8.6
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-21
Original CVE updated
2026-06-22
Advisory published
2026-06-21
Advisory updated
2026-06-22

Who should care

Defenders responsible for Craft CMS installations, particularly those with versions between 5.5.0 and 5.9.13, should prioritize patching to prevent potential remote code execution attacks. Additionally, security teams monitoring for potential exploitation attempts and administrators responsible for system hardening should be aware of this vulnerability.

Technical summary

The vulnerability exists in the FieldsController::actionRenderCardPreview() method of Craft CMS. Specifically, the method passes the fieldLayoutConfig POST parameter directly to Fields::createLayout() without calling Component::cleanseConfig(). This oversight allows an authenticated admin user to inject Yii2 event handlers, such as 'on init' keys, via the fieldLayoutConfig parameter. Successful exploitation enables the execution of arbitrary PHP code and disclosure of sensitive information, including environment variables containing database credentials and CRAFT_SECURITY_KEY.

Defensive priority

High priority due to CVSS score of 8.6 and potential for significant impact

Recommended defensive actions

  • Apply the official patch by updating Craft CMS to version 5.9.14 or later
  • Inventory Craft CMS installations to identify potentially vulnerable versions
  • Review official advisories for additional guidance
  • Monitor for potential exploitation attempts
  • Implement compensating controls to limit exposure

Evidence notes

The primary evidence for this vulnerability comes from the CVE-2026-56382 record and associated source references. The vulnerability affects Craft CMS versions >= 5.5.0 and <= 5.9.13. Defenders should verify the version of Craft CMS in use and confirm the presence of the fix in version 5.9.14. Evidence limits are based on information available up to the CVE publication date.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-56382 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-56382

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-56382 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-56382

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.