CVE-2026-81912Network attack vectorHinoki check available

Authorization changes via tokenless group moves

Published Sep 11, 2026 · Updated Sep 11, 2026

Cross-site request forgery in Concrete CMS before 9.5.3 allows remote attackers to move user groups through an authenticated administrator. The dashboard/users/groups/bulkupdate/confirm() endpoint moved selected group-tree nodes without validating the bulk-update action token. Exploitation requires an authenticated administrator to submit a forged request; the move changes member authorization through inherited parent-group permissions.

CVSS severity5.7
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
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Summary

What happened

Cross-site request forgery in Concrete CMS before 9.5.3 allows remote attackers to move user groups through an authenticated administrator. The dashboard/users/groups/bulkupdate/confirm() endpoint moved selected group-tree nodes without validating the bulk-update action token. Exploitation requires an authenticated administrator to submit a forged request; the move changes member authorization through inherited parent-group permissions.

The record

CVE
CVE-2026-81912
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
Concrete CMS
Product
Concrete CMS
Classifications
CWE-352, T1204.001
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.0.0 <=9.5.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Concrete CMS · Concrete CMSversion=5.0.0 <=9.5.2

Published CVSS scores

5.7Concrete CMS Security TeamCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-352Cross-Site Request Forgery (CSRF)
T1204.001User Execution: Malicious Link

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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