CVE-2026-81916Network attack vector

Unauthorized entry creation via mismatched Express object checks

Published Sep 11, 2026 · Updated Sep 11, 2026

Incorrect authorization in Concrete CMS before 9.5.3 allows remote authenticated users to create entries in unauthorized Express objects. The dashboard submit route mutates the object named by its route ID but checks permission against the independently posted form object's entity without comparing them. A high-privileged account needs add permission on one Express object; exploitation writes records into another object's protected dataset.

CVSS severity5.1
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Concrete CMS before 9.5.3 allows remote authenticated users to create entries in unauthorized Express objects. The dashboard submit route mutates the object named by its route ID but checks permission against the independently posted form object's entity without comparing them. A high-privileged account needs add permission on one Express object; exploitation writes records into another object's protected dataset.

The record

CVE
CVE-2026-81916
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
Concrete CMS
Product
Concrete CMS
Classifications
T1565.001
Attack vector
network
Privileges
authenticated

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 privilegesauthenticated

What is affected?

Concrete CMS · Concrete CMSversion=5.0.0 <=9.5.2

Published CVSS scores

5.1Concrete CMS security teamCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1565.001Stored Data Manipulation

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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