What’s Vulnerable › Vulnerabilities

CVE-2026-112777: Craft CMS before 4.18.8 and 5.11.0 Twig create() Blocklist Bypass Leading to RCE

• Severity: high (CVSS 7.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-19 · updated 2026-10-20
• Weakness: CWE-184

Description

Craft CMS 4.x before 4.18.8 and 5.x before 5.11.0 contains a blocklist bypass in the Twig create() function because its class-name checks are case-sensitive while PHP class resolution is not. Attackers with template-execution rights, such as Control Panel administrators, can instantiate SplFileObject via a lowercase class name to read .env secrets or write a PHP file into the webroot for remote code execution.

Affected products

• craftcms cms: from 4.0.0 before 4.18.8; from 5.0.0 before 5.11.0 — fixed in 4.18.8, 5.11.0

How to fix

Upgrade to a fixed version: craftcms cms 4.18.8, 5.11.0. Check the vendor advisory for mitigations.

References

• https://github.com/craftcms/cms/security/advisories/GHSA-w643-x88w-6wcm
• https://www.vulncheck.com/advisories/craft-cms-before-4.18.8-and-5.11.0-twig-create-blocklist-bypass-leading-to-rce

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