CVE-2026-81904 — Concrete CMS before 9.5.3 is vulnerable to Missing Authorization in Stack/Container Sub-Block Asset Registration

Description (CNA)

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 (CNA)

Vendor / product	Versions
Concrete CMS / Concrete CMS	affected 5 through 9.5.2

CWE

CWE-862

References

https://documentation.concretecms.org/9-x/developers/introduction/version-history/953-release-notes

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.