IDOR in Concrete CMS 9.0.0 through 9.5.2 dashboard sitemap reorder (SitemapUpdate::updateDisplayOrder) allows an authenticated sitemap user to reorder arbitrary pages

published 2026-09-15 last mo. modified 2026-09-21 last mo. also EUVD-2026-79504

cvss: 2.7; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits: 0; none known

Concrete CMS 9 before 9.5.3 authorized the dashboard sitemap reorder action (Concrete\Controller\Backend\Dashboard\SitemapUpdate) using only the global access_sitemap task permission and did not check per-page edit permission before updating each page's display order. As a result, an authenticated user granted sitemap access could change the display order (cDisplayOrder) of any pages they had no rights to edit, altering the order in which those pages render in navigation, breadcrumb, and page-list output. The reorder action additionally validated no CSRF token, so the write could be triggered by a forged request. 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 Winston Crooker for reporting.

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CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: last mo. (2026-09-20)

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	4.0	2.1	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
CNA	4.0	2.1	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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD	3.1	2.7	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N

Affected products

Concrete CMS Concrete CMS

Classification

Weakness

CWE-862 Missing Authorization
CWE-352 Cross-Site Request Forgery

References

documentation.concretecms.org /developers/introduction/version-history/953-release-notes
release-notes, broken-link

Sources

CVE List CVE-2026-18425
NVD CVE-2026-18425

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CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.