# CVE-2026-44401: Typemill CMS 2.x Persistent XSS via Markdown javascript URI

> Authenticated attackers can inject malicious JavaScript via Markdown links in Typemill CMS, leading to session theft and credential harvesting for site visitors.

- **Severity:** Medium 4.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 10 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** GHSA-8vfw-vh7q-p649

## What is CVE-2026-44401?

CVE-2026-44401 is a medium-severity cross-site scripting vulnerability in Typemill, published on 10 Aug 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Typemill CMS version 2.x contains a persistent cross-site scripting vulnerability in the Markdown parser extension that allows authenticated users with theme-configuration access to inject malicious JavaScript URIs by supplying unsanitized href values in Markdown links. Attackers can craft Markdown links using the javascript: scheme through ParsedownExtension.php or TwigMarkdownExtension.php, storing a persistent payload that executes in the browser of every visitor who clicks the link, enabling session cookie theft, authenticated request forgery, and credential harvesting.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-44401?


## How do I fix CVE-2026-44401?

No fix has been published for CVE-2026-44401 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-44401 being exploited?

There is no known exploitation of CVE-2026-44401 in the wild and no public exploit code.

Public exploit code:

- Persistent XSS in Typemill CMS: the Markdown parser lets javascript: URIs through unfiltered. Writeup + PoC. (github_poc): https://github.com/sn0x-sharma/CVE-2026-44401

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-44401 and fix it if it is affected.

What it is: CVE-2026-44401 is a medium-severity cross-site scripting vulnerability in Typemill, published on 10 Aug 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-44401 in the wild and no public exploit code.

Affected product: Typemill. 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-2026-44401/ (Markdown: https://insights.sbomify.com/CVE-2026-44401/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-44401
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-44401
- OSV: https://osv.dev/vulnerability/CVE-2026-44401

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-44401/
Summaries are generated and may contain mistakes; the official description above is the record.