# CVE-2026-81912

## Summary

- **CVE ID:** CVE-2026-81912
- **Severity:** MEDIUM
- **CVSS Score:** 5.7 (CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N)
- **CWE:** CWE-352
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 11, 2026

## Description

Concrete CMS before 9.5.3 is vulnerable to Cross-Site Request Forgery in the Move Multiple Groups feature. The dashboard/users/groups/bulkupdate/confirm() endpoint moved the selected group tree nodes without validating an action token, so a state-changing group move could be processed for an authenticated user who did not initiate it. Because relocating a group under a new parent causes that group's members to inherit the parent's permissions, a forged move can change effective authorization. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.7 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks riodrwn for reporting.

## Affected Products

- Concrete CMS — Concrete CMS (5.0.0)

## References

- [CNA](https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes)

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-12._