---
title: "CVE-2026-81901: Concrete CMS - Stored XSS"
description: "Concrete CMS 9.2.0 through 9.5.2 contains a stored XSS caused by missing authorization checks on page properties, templates, and types in the REST API page update endpoint, letting users with content-editing rights persist JavaScript executing in visitors' browsers, exploit requires user with content-editing rights."
url: https://panop.io/threat-heartbeat/CVE-2026-81901/
---

# CVE-2026-81901 Concrete CMS - Stored XSS

Concrete CMS 9.2.0 through 9.5.2 contains a stored XSS caused by missing authorization checks on page properties, templates, and types in the REST API page update endpoint, letting users with content-editing rights persist JavaScript executing in visitors' browsers, exploit requires user with content-editing rights.

CVSS base score 8.7 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.38% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-81901)

## Details

Type

Stored XSS

Impact

Stored XSS

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Published

14 September 2026

Updated

15 October 2026

Weakness

[CWE-862](https://cwe.mitre.org/data/definitions/862.html)

## Vendor fix

Update to a version later than 9.5.2 or the latest available version.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-81901](https://nvd.nist.gov/vuln/detail/CVE-2026-81901)
- [https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes](https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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