# CVE-2026-112777: Craft CMS blocklist bypass in Twig create() function

Source: https://junglewise.ai/threats/cve-2026-112777-craft-cms-4-x-before-4-18-8-and-5-x-before-5-11-0-contains-a  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-19. Updated: 2026-10-19  
License: CC BY 4.0 with a link back

CVE-2026-112777 · Severity: high · CVSS 7.2 · Published 2026-10-19

Craft CMS is a content management system used to build and manage websites. Attackers with administrator access to the Control Panel can bypass security restrictions in the Twig template engine's create() function to read sensitive files like .env configuration files containing database credentials, or write malicious PHP files to execute code on the server.

Technologies: [Craft CMS](https://junglewise.ai/threats/technologies/craft-cms-1). Vendors: [Craft](https://junglewise.ai/threats/vendors/craft).

## Quick answers

**Is CVE-2026-112777 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-112777 being exploited in the wild.

**How severe is CVE-2026-112777?** High severity, with a CVSS score of 7.2, published 19 October 2026.

**Which products and versions are affected?** Craft CMS 4.x before 4.18.8, 5.x before 5.11.0.

**Is there a fix for CVE-2026-112777?** Yes: fixed in 4.18.8, 5.11.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-112777 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-112777?** Check whether you run Craft CMS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 4.18.8, 5.11.0

## Technical details

A case-sensitivity mismatch in the blocklist checks for Craft's Twig create() function allows attackers to instantiate SplFileObject by passing the class name in lowercase ("splfileobject"). The str_starts_with() and str_ends_with() checks are case-sensitive while PHP class resolution is case-insensitive, and the lowercase variant was removed from the case-insensitive blocklist. An attacker with template-execution rights (e.g., Control Panel administrator) can read arbitrary files or write PHP shells to achieve remote code execution.

## Affected products

- Craft CMS 4.x before 4.18.8, 5.x before 5.11.0

## Timeline

- 2026-10-05: disclosed
- 2026-10-19: advisory

## References

- [https://github.com/craftcms/cms/security/advisories/GHSA-w643-x88w-6wcm](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](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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