Formie: Unauthenticated users can overwrite incomplete submissions via submit action

[ Description ]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.

[ Fixes ]Fixes and patches

• verbb/formie 3.1.31Fixed version · GitHub Advisories · composer package verbb/formie: upgrade to 3.1.31 or later (affected >= 3.0.0, < 3.1.31)
• verbb/formie 2.2.23Fixed version · GitHub Advisories · composer package verbb/formie: upgrade to 2.2.23 or later (affected < 2.2.23)

[ Packages ]Affected open-source packages

• verbb/formie composerAffected >= 3.0.0, < 3.1.31 · fixed in 3.1.31 · GHSA-584p-f93j-wpgc
• verbb/formie composerAffected < 2.2.23 · fixed in 2.2.23 · GHSA-584p-f93j-wpgc

[ References ]References

• github.com/verbb/formie/commit/323c2fe647a76fbccadf749728ee4ad9420efee1
• github.com/verbb/formie/commit/78a298ac3baf85ac283988dfce9cd42c9b958f16
• github.com/verbb/formie/releases/tag/2.2.23
• github.com/verbb/formie/releases/tag/3.1.31
• github.com/verbb/formie/security/advisories/GHSA-584p-f93j-wpgc