# CVE-2026-81904

## Summary

- **CVE ID:** CVE-2026-81904
- **Severity:** MEDIUM
- **CVSS Score:** 6.3 (CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N)
- **CWE:** CWE-862
- **Published:** Sep 8, 2026
- **Last Modified:** Sep 9, 2026

## Description

Concrete CMS below 9.5.3 registered view assets for every sub-block of a Stack, Container, or layout area without checking whether the requesting user could view that sub-block. An unauthenticated visitor could recover configuration values emitted by a restricted sub-block's asset registration — such as a site's configured Google Maps API key — from any public page embedding an affected Stack, Container, or layout area, despite the block-level permission restriction. Any sub-block type whose asset or header hooks output configuration values is affected.  The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori (Tenzai) for reporting.

## Affected Products

- Concrete CMS — Concrete CMS (5)

## References

- [CNA](https://documentation.concretecms.org/9-x/developers/introduction/version-history/953-release-notes)

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