PatchSiren cyber security CVE debrief
CVE-2026-47266 verbb CVE debrief
CVE-2026-47266 is a HIGH severity (CVSS 8.7) authorization bypass in the Formie plugin for Craft CMS. Unauthenticated attackers can modify existing form submissions by submitting a known or guessed submission ID to the `formie/submissions/save-submission` endpoint. The vulnerability affects versions prior to 2.2.21 (v2.x branch) and 3.1.26 (v3.x branch). The issue was disclosed on 2026-05-29 with fixes released the same day. No known exploitation in ransomware campaigns has been reported.
- Vendor
- verbb
- Product
- formie
- CVSS
- HIGH 8.7
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-05-29
- Original CVE updated
- 2026-05-29
- Advisory published
- 2026-05-29
- Advisory updated
- 2026-05-29
Who should care
Organizations running Craft CMS with the Formie plugin for form management, particularly those handling sensitive submission data or compliance-regulated information. Security teams should prioritize patching due to the unauthenticated attack vector and data integrity impact.
Technical summary
The Formie plugin's `formie/submissions/save-submission` endpoint fails to properly validate ownership or session state when processing submission updates. By providing a valid submission ID, unauthenticated attackers can overwrite existing submission data. The vulnerability stems from missing authorization checks that would verify the submitter's right to modify the targeted submission.
Defensive priority
HIGH
Recommended defensive actions
- Upgrade Formie to version 2.2.21 or later (v2.x) or 3.1.26 or later (v3.x)
- Review form submission logs for unauthorized modifications to existing submissions
- Implement additional access controls or rate limiting on form submission endpoints if immediate patching is not feasible
- Audit existing submissions for data integrity, particularly those with sequential or predictable IDs
Evidence notes
The vulnerability description and fix versions are sourced from the official CVE record and GitHub Security Advisory. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N) confirms network-accessible, unauthenticated attack with high integrity impact. CWE-639 (Authorization Bypass Through User-Controlled Key) is the assigned weakness.
Official resources
2026-05-29