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


- **Severity:** Medium 6.9 (`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`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 1 Mar 2026
- **Updated:** 2 Mar 2026
- **Also known as:** GHSA-g6fv-7p3q-j4fc

## What is CVE-2026-3395?

CVE-2026-3395 is a medium-severity vulnerability in MaxSite CMS, published on 1 Mar 2026. 

### Official 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.

Weakness: CWE-94 (Improper Control of Generation of Code), CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2026-3395?

It affects 1 product.


Products: Max-3000 Maxsite Cms.

## How do I fix CVE-2026-3395?

No fix has been published for CVE-2026-3395 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-3395 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3395 exists.

Public exploit code:

- https://github.com/mbanyamer/CVE-2026-3395-MaxSite-CMS-Unauthenticated-RCE (github_poc): https://github.com/mbanyamer/CVE-2026-3395-MaxSite-CMS-Unauthenticated-RCE
- https://github.com/rootdirective-sec/CVE-2026-3395-Lab (github_poc): https://github.com/rootdirective-sec/CVE-2026-3395-Lab
- MaxSite CMS <=109.1 - Remote Code Execution (nuclei): http/cves/2026/CVE-2026-3395.yaml

## Other vulnerabilities in MaxSite CMS

- [CVE-2022-25411](https://insights.sbomify.com/CVE-2022-25411/): File upload in n/a (critical 9.8)
- [CVE-2021-27983](https://insights.sbomify.com/CVE-2021-27983/): Code injection in n/a (critical 9.8)
- [CVE-2022-25412](https://insights.sbomify.com/CVE-2022-25412/): Path traversal in n/a (high 8.1)
- [CVE-2022-25410](https://insights.sbomify.com/CVE-2022-25410/): Cross-site scripting in n/a (medium 5.4)
- [CVE-2022-25413](https://insights.sbomify.com/CVE-2022-25413/): Cross-site scripting in n/a (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3395 and fix it if it is affected.

What it is: CVE-2026-3395 is a medium-severity vulnerability in MaxSite CMS, published on 1 Mar 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3395 exists.

Affected product: MaxSite CMS. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-3395/ (Markdown: https://insights.sbomify.com/CVE-2026-3395/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3395
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3395
- OSV: https://osv.dev/vulnerability/CVE-2026-3395

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3395/
Summaries are generated and may contain mistakes; the official description above is the record.