Auth bypass in Concrete Cms

CVE-2026-81922

Concrete CMS before 9.5.3 did not enforce a per-page authorization check when reordering pages from the sitemap. In the sitemap Explore dashboard controller, the send_to_top and send_to_bottom reorder tasks ran after only a generic sitemap-access check; the controller loaded the page named by the attacker-controlled cNodeID parameter and changed its display order without verifying that the current user held move or arrange permission on that specific page. Because of this, an authenticated user who could reach the sitemap but had no edit or arrange rights on a given page could still move that page and alter the site's global navigation order. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.1 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Andrew Gonzalez for reporting.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 2.7 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (22.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-81922: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-81922?
CVE-2026-81922 is a low-severity vulnerability in Concrete Cms, classified under Missing Authorization. CVSS score: 2.7/10. Published 2026-09-15.
How severe is CVE-2026-81922?
Low severity. CVSS v3 base score is 2.7 out of 10.