---
title: "CVE-2026-85385: Concrete CMS - Stored XSS"
description: "Concrete CMS < 9.5.4 contains a stored cross-site scripting caused by lack of validation and output encoding of user timezone value on the Dashboard user management page, letting attackers execute scripts in administrator sessions, exploit requires concrete.misc.user_timezones enabled and either authenticated user or public registration enabled."
url: https://panop.io/threat-heartbeat/CVE-2026-85385/
---

# CVE-2026-85385 Concrete CMS - Stored XSS

Concrete CMS < 9.5.4 contains a stored cross-site scripting caused by lack of validation and output encoding of user timezone value on the Dashboard user management page, letting attackers execute scripts in administrator sessions, exploit requires concrete.misc.user\_timezones enabled and either authenticated user or public registration enabled.

CVSS base score 9.6 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.50% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-85385)

## Details

Type

Stored XSS

Impact

Stored XSS

CVSS vector

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

Published

16 September 2026

Updated

15 October 2026

Weakness

[CWE-79](https://cwe.mitre.org/data/definitions/79.html)

## Vendor fix

Update to version 9.5.4 or later.

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-2026-85385](https://nvd.nist.gov/vuln/detail/CVE-2026-85385)
- [https://documentation.concretecms.org/developers/introduction/version-history/954-release-notes](https://documentation.concretecms.org/developers/introduction/version-history/954-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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