# CVE-2026-46492: md-fileserver: Stored/Reflected XSS when viewing Markdown (raw HTML allowed)

> An attacker can execute arbitrary JavaScript in the victim's browser by crafting malicious Markdown files with raw HTML tags.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Jun 2026
- **Updated:** 9 Jun 2026
- **Also known as:** GHSA-32q2-hhr5-6qvv

## What is CVE-2026-46492?

CVE-2026-46492 is a high-severity cross-site scripting vulnerability in commenthol md-fileserver, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

md-fileserver allows for local viewing of markdown files in a browser. Prior to version 1.10.3, a cross-site scripting (XSS) vulnerability exists in the application’s Markdown rendering logic. When user-supplied Markdown content is rendered, embedded raw HTML—including <script> tags—is processed and injected into the resulting page without sanitization, allowing arbitrary JavaScript execution in the context of the affected domain. This issue has been patched in version 1.10.3.

Weakness: CWE-87 (Improper Neutralization of Alternate XSS Syntax), CWE-80 (Improper Neutralization of Script-Related HTML Tags in a Web Page)

## Which versions are affected by CVE-2026-46492?

2 open source packages ship an affected version, including md-fileserver. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `md-fileserver` | npm | All versions | 1.10.3 |
| `md-fileserver` | npm | All versions | 1.10.3 |

Products: Commenthol Md-Fileserver.

## How do I fix CVE-2026-46492?

Upgrade md-fileserver to 1.10.3 or later.

## Is CVE-2026-46492 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-46492 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46492 and fix it if it is affected.

What it is: CVE-2026-46492 is a high-severity cross-site scripting vulnerability in commenthol md-fileserver, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-46492 exists.

Affected packages and fixed versions:
- md-fileserver (npm): affected all versions; fixed in 1.10.3
- md-fileserver (npm): affected all versions; fixed in 1.10.3

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-2026-46492/ (Markdown: https://insights.sbomify.com/CVE-2026-46492/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46492
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46492
- OSV: https://osv.dev/vulnerability/CVE-2026-46492

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46492/
Summaries are generated and may contain mistakes; the official description above is the record.