CVE-2026-76087 Formie: Unauthenticated users can overwrite incomplete submissions via submit action
Unauthenticated attackers can overwrite other users' incomplete form submissions by manipulating submission IDs, leading to data modification and potential exposure.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-76087?
CVE-2026-76087 is a high-severity missing authorization vulnerability in verbb formie, published on 23 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Formie is a Craft CMS plugin for creating forms. Prior to 2.2.23 and 3.1.31, Formie's anonymous formie/submissions/submit action in SubmissionsController::actionSubmit trusts a client-supplied submissionId when loading an incomplete submission without session binding, ownership validation, or a valid submissionEditToken. An unauthenticated attacker can enumerate sequential IDs and overwrite or hijack another user's in-progress multi-page or save-for-later submission, and the modified data can be persisted and forwarded through notifications or integrations when the submission is completed. This is an incomplete remediation of CVE-2026-47266 because that earlier change validated edit tokens for save-submission but did not protect submit. Completed submissions are excluded by the isIncomplete filter. This issue is fixed in versions 2.2.23 and 3.1.31.
Which versions are affected by CVE-2026-76087?
4 open source packages ship an affected version, including verbb/formie.
| Package | Affected | Fixed in |
|---|---|---|
verbb/formie Packagist | All versions | 2.2.23 |
verbb/formie Packagist | All versions | 2.2.23 |
verbb/formie Packagist | From 3.0.0 | 3.1.31 |
verbb/formie Packagist | From 3.0.0 | 3.1.31 |
How do I fix CVE-2026-76087?
Upgrade verbb/formie to a fixed version for your release line: 2.2.23 or 3.1.31.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-76087 being exploited?
There is no known exploitation of CVE-2026-76087 in the wild and no public exploit code.
Sources
Also known as GHSA-584p-f93j-wpgc.