CVE-2026-45697: Formie: Pre-authenticated server-side template injection in Hidden fields

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-29 · updated 2026-07-22
Weakness: CWE-94

Description

Formie is a Craft CMS plugin for creating forms. Prior to 2.2.20 and 3.1.24, unauthenticated users could submit crafted values into Hidden fields (with Default value → Custom) that were evaluated as Twig during submission handling, which could lead to serious compromise of the Craft site (depending on template/sandbox behavior). This vulnerability is fixed in 2.2.20 and 3.1.24.

Affected products

verbb formie: before 2.2.20; from 3.0.0-beta.1, < 3.1.24

References

https://github.com/verbb/formie/commit/f690d5623163ce2a95da305238d6367575486ee3
https://github.com/verbb/formie/releases/tag/2.2.20
https://github.com/verbb/formie/releases/tag/3.1.24
https://github.com/verbb/formie/security/advisories/GHSA-x7m9-mwc2-g6w2

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