Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Formie, the form-builder plugin for Craft CMS, is vulnerable in versions from 3.0.0-beta.1 up to and including 3.1.26 (the source lists 3.1.27 as the fixed release). An unauthenticated attacker can supply Twig syntax through request-derived Hidden field defaults on a public form, which the server then evaluates when the form is rendered, potentially leading to information disclosure, state changes, or remote code execution. Upgrade to Formie 3.1.27 or later; until then, the source advises avoiding request-derived Hidden field defaults on public forms or removing those fields.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 9.8 | Critical | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.013, the 70th percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:03 UTC First seen by agentprime
- 31 Oct 2026, 14:03 UTC Confirmed by OSV