Back

CRITICAL

Formie: Server-Side Template Injection in Formie Hidden field defaults

Published Aug 19, 2026

Description

Formie is a Craft CMS plugin for creating forms. Prior to 3.1.27, Formie can pass request-derived Hidden field defaults such as HTTP User Agent, Referer URL, Current URL, Current URL without Query String, Query Parameter, and Cookie Value to Craft's Twig rendering layer during front-end form rendering. An unauthenticated attacker can place Twig syntax in one of these request-controlled inputs when a public form contains an affected Hidden field. Hidden::getFrontEndInputOptions() then assigns the value to defaultValue and calls renderString, causing server-side template evaluation rather than treating the request data as a plain string. Depending on the Craft site configuration and available Twig capabilities, exploitation can disclose sensitive information, modify application state, or achieve remote code execution. This issue is fixed in version 3.1.27.

Affected products

Remediation

No remediation recorded yet.

Weaknesses (1)

References (5)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner GitHub_M
Published Aug 19, 2026
Updated Aug 19, 2026
Reserved Jun 8, 2026
CISA Vulnrichment
Updated Aug 19, 2026
NVD
Status Deferred
Modified Sep 10, 2026
Red Hat
Severity n/a
Public date n/a
ENISA EUVD
Assigner GitHub_M
Published Aug 19, 2026
Updated Aug 19, 2026
Exploited since n/a
EUVD-2026-62518 GHSA-565M-G33J-JQ96