CVE-2022-46180 — Discourse Mermaid (discourse-mermaid-theme-component) allows users of Discourse,

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. Th

01What is this vulnerability?

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…

02Affected products

Vendor	Product	Versions
discourse	discourse	mermaid-theme-component — = 1.0.0

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-01-04T16:44:54.487Z
• Last modified: 2025-03-10T21:32:39.201Z

09References

• github.com — https://github.com/discourse/discourse-mermaid-theme-component/security/advisori…
• github.com — https://github.com/discourse/discourse-mermaid-theme-component/pull/14
• github.com — https://github.com/discourse/discourse-mermaid-theme-component/commit/c10bc4a08b…