---
title: "CVE-2026-88418: CMSimple - Stored XSS & Remote Code Execution"
description: "CMSimple 5.24 contains a stored XSS and remote code execution caused by disabled CSRF protection and unsanitized scripting markers in admin content saving, letting unauthenticated attackers execute arbitrary PHP code via a logged-in admin's browser."
url: https://panop.io/threat-heartbeat/CVE-2026-88418/
---

# CVE-2026-88418 CMSimple - Stored XSS & Remote Code Execution

CMSimple 5.24 contains a stored XSS and remote code execution caused by disabled CSRF protection and unsanitized scripting markers in admin content saving, letting unauthenticated attackers execute arbitrary PHP code via a logged-in admin's browser.

CVSS base score 8.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.25% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-88418)

## Details

Type

Stored XSS

Impact

Remote Code Execution

CVSS vector

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

Published

22 September 2026

Updated

15 October 2026

Weakness

[CWE-352](https://cwe.mitre.org/data/definitions/352.html)

## Vendor fix

Enable CSRF protection by default and sanitize scripting markers in admin content saving; update to the latest CMSimple 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-2026-88418](https://nvd.nist.gov/vuln/detail/CVE-2026-88418)
- [https://github.com/15536818056/CVE/issues/5](https://github.com/15536818056/CVE/issues/5)

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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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