# CVE-2022-46180: Arbitrary HTML injection in discourse-mermaid-theme-component

> Attackers can inject arbitrary HTML into posts via the Discourse Mermaid theme component, potentially leading to script execution or account takeover.

- **Severity:** Medium 5.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Jan 2023
- **Updated:** 10 Mar 2025
- **Also known as:** GHSA-8437-hgcm-p3q3

## What is CVE-2022-46180?

CVE-2022-46180 is a medium-severity cross-site scripting vulnerability in discourse-mermaid-theme-component, published on 4 Jan 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Discourse Mermaid (discourse-mermaid-theme-component) allows users of Discourse, open-source forum software, to create graphs using the Mermaid syntax. Users of discourse-mermaid-theme-component version 1.0.0 who can create posts are able to inject arbitrary HTML on that post. The issue has been fixed on the `main` branch of the GitHub repository, with 1.1.0 named as a patched version. Admins can update the theme component through the admin UI. As a workaround, admins can temporarily disable discourse-mermaid-theme-component.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2022-46180?

It affects 1 product.


Products: Discourse Mermaid.

## How do I fix CVE-2022-46180?

No fix has been published for CVE-2022-46180 yet. Limit exposure of the affected software until one is available.

## Is CVE-2022-46180 being exploited?

There is no known exploitation of CVE-2022-46180 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-46180 and fix it if it is affected.

What it is: CVE-2022-46180 is a medium-severity cross-site scripting vulnerability in discourse-mermaid-theme-component, published on 4 Jan 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-46180 in the wild and no public exploit code.

Affected product: discourse-mermaid-theme-component. 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-2022-46180/ (Markdown: https://insights.sbomify.com/CVE-2022-46180/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-46180
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-46180
- OSV: https://osv.dev/vulnerability/CVE-2022-46180

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-46180/
Summaries are generated and may contain mistakes; the official description above is the record.