Auth bypass in Concrete Cms
CVE-2026-81904
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.
Vulnerability class: Broken Access Control
Published · last modified .
EPSS exploit prediction
EPSS: 0.005 (39.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 39.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000