CVE-2026-109304 craftcms CVE debrief

Who should care

Defenders responsible for Craft CMS installations, particularly those with user-controlled entry-type title formats, should assess exposure and apply patches. They should also review compensating controls for exposed systems while remediation is scheduled and verified, and monitor for potential file reads and unauthorized access. Additionally, defenders should track exceptions, retest remediated assets, and close the item only after evidence is documented.

Why it matters

CVE-2026-109304 is a medium-severity vulnerability in Craft CMS that allows for arbitrary file reads. Defenders should prioritize verifying exposure and applying patches to prevent potential unauthorized file reads and exposure of sensitive local file contents.

• Potential unauthorized file reads
• Possible exposure of sensitive local file contents
• Required verification of Craft CMS versions and configurations
• Need for patch application to prevent exploitation

Technical summary

The vulnerability exists in the Twig create() class blocklist, which does not cover DOMDocument. Attackers can use create('DOMDocument').loadHTMLFile() with textContent to expose local file contents. This allows for arbitrary file reads in Craft CMS 4.0.0 before 4.18.7 and 5.0.0 before 5.10.14. The vulnerability can be exploited by attackers with the ability to set an entry-type title format, including via project-config/apply, to expose local file contents to non-admin users who can view entries. Defenders should prioritize verifying exposure and applying patches to prevent potential unauthorized file reads and exposure of sensitive local file contents.

Defensive priority

Defenders should prioritize verifying exposure and applying patches, focusing on systems with user-controlled entry-type title formats.

Recommended defensive actions

• Verify exposure by checking Craft CMS versions and configurations
• Apply patches to update to Craft CMS 4.18.7 or 5.10.14
• Restrict access to entry-type title formats to prevent exploitation
• Monitor for potential file reads and unauthorized access
• 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

Evidence notes

The CVE Program record and NVD vulnerability detail provide official information on the vulnerability. Supplemental sources include a GitHub Security Advisory and a VulnCheck Advisory. The vulnerability allows for arbitrary file reads via the Twig create() DOMDocument in Craft CMS 4.0.0 before 4.18.7 and 5.0.0 before 5.10.14. Defenders should verify exposure and apply patches, focusing on systems with user-controlled entry-type title formats.

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.