CVE-2026-109305 craftcms CVE debrief

Who should care

Defenders responsible for Craft CMS instances should assess exposure and prioritize patching or mitigating this vulnerability. This includes reviewing affected versions, restricting access to the System Messages permission, and monitoring for suspicious activity. Operators of Craft CMS instances, platform administrators, and security teams should be aware of this vulnerability and take necessary actions to protect their systems.

Why it matters

CVE-2026-109305 is a high-severity vulnerability in Craft CMS that allows for remote code execution. Defenders responsible for Craft CMS instances should assess exposure and prioritize patching or mitigating this vulnerability.

• Remote code execution is possible for users with the System Messages permission
• Defenders must verify affected versions and prioritize patching
• Compensating controls such as restricting access to the System Messages permission may be necessary
• Monitoring for suspicious activity in Craft CMS instances is recommended

Technical summary

The vulnerability is a Twig sandbox bypass that allows non-admin users to invoke PHP callables through the 'has some' and 'has every' operators. Users with the System Messages permission can supply two-argument callables such as passthru or system in sandboxed templates to execute code as the web user. This vulnerability affects Craft CMS versions from 5.10.2 before 5.10.14. The vulnerability allows for remote code execution, making it a high-severity issue with a CVSS score of 8.7. Defenders should prioritize patching or mitigating this vulnerability.

Defensive priority

Defenders should prioritize patching or mitigating this vulnerability, as it allows for remote code execution.

Recommended defensive actions

• Patch Craft CMS to version 5.10.14 or later
• Restrict access to the System Messages permission
• Monitor for suspicious activity in Craft CMS instances
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability is described in the CVE Program record and the NVD vulnerability detail page. The source item provides additional information about the vulnerability, including affected versions and references to vendor advisories.

Sources and 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.