CVE-2026-28697 PUBLISHED

Craft Affected by Authenticated RCE via "craft.app.fs.write()" in Twig Templates

Assigner: GitHub_M
Reserved: 02.03.2026 Published: 04.03.2026 Updated: 04.03.2026

Craft is a content management system (CMS). Prior to 4.17.0-beta.1 and 5.9.0-beta.1, an authenticated administrator can achieve Remote Code Execution (RCE) by injecting a Server-Side Template Injection (SSTI) payload into Twig template fields (e.g., Email Templates). By calling the craft.app.fs.write() method, an attacker can write a malicious PHP script to a web-accessible directory and subsequently access it via the browser to execute arbitrary system commands. This vulnerability is fixed in 4.17.0-beta.1 and 5.9.0-beta.1.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
CVSS Score: 9.4

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	High
Attack Complexity	Low	Integrity	High	Integrity	High
Attack Requirements	None	Availability	High	Availability	High
Privileges Required	High
User Interaction	None

CVSS 4.0

Product Status

Vendor	craftcms
Product	cms
Versions	Version >= 5.0.0-RC1, < 5.9.0-beta.1 is affected Version >= 4.0.0-RC1, < 4.17.0-beta.1 is affected

References

Problem Types

CWE-1336: Improper Neutralization of Special Elements Used in a Template Engine CWE