formie's unauthenticated front-end submission editing can overwrite existing submissions

### Impact Unauthenticated users could modify existing submissions by posting a known or guessed submission ID to `formie/submissions/save-submission`. ### Patches [2.2.21](https://github.com/verbb/formie/releases/tag/2.2.21), [3.1.26](https://github.com/verbb/formie/releases/tag/3.1.26) ### Workarounds Block unauthenticated access to `actions/formie/submissions/save-submission`, or disable/customize front-end submission editing until patched. ### Credit formie extends many thanks to: - Florian (Cyber Security Engineer, arcade solutions ag) - Contact: [security@arcade.ch](mailto:security@arcade.ch) Source Code Location: https://github.com/verbb/formie Affected Packages: - composer:verbb/formie, affected >= 3.0.0, < 3.1.26, patched in 3.1.26 - composer:verbb/formie, affected < 2.2.21, patched in 2.2.21 CWEs: - CWE-639: Authorization Bypass Through User-Controlled Key CVSS: - CVSS_V4: score 8.7, CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X References: - https://github.com/verbb/formie/security/advisories/GHSA-pgxq-p76c-x9cg - https://nvd.nist.gov/vuln/detail/CVE-2026-47266 - https://github.com/verbb/formie/releases/tag/2.2.21 - https://github.com/verbb/formie/releases/tag/3.1.26 - https://github.com/advisories/GHSA-pgxq-p76c-x9cg