# CVE-2026-72730: Discourse stored XSS in Rich Text Editor chat transcript username

Source: https://junglewise.ai/threats/cve-2026-72730-discourse-stored-xss-in-rich-text-editor-chat-transcript-username  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-10. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-72730 · Severity: high · CVSS 8.7 · Published 2026-08-10

Discourse is an open-source discussion platform used for online communities and team collaboration. A vulnerability in the Rich Text Editor failed to escape usernames in chat transcripts, allowing attackers to inject malicious HTML and JavaScript code. When users view affected chat transcripts, the injected code executes in their browsers, potentially enabling account theft, session hijacking, or data theft from community members.

Technologies: [Discourse](https://junglewise.ai/threats/technologies/discourse). Vendors: [Discourse](https://junglewise.ai/threats/vendors/discourse).

## Quick answers

**Is CVE-2026-72730 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-72730 being exploited in the wild.

**How severe is CVE-2026-72730?** High severity, with a CVSS score of 8.7, published 10 August 2026.

**Which products and versions are affected?** Discourse prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.

**Is there a fix for CVE-2026-72730?** A patch was published on 2026-01-06: version 2026.1.6 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-72730 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-72730?** Check whether you run Discourse at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

This is a stored cross-site scripting (XSS) vulnerability in Discourse's Rich Text Editor component. The vulnerable code fails to properly HTML-escape usernames when rendering chat-transcript content, allowing an attacker to embed malicious JavaScript in a username. When other users view the chat transcript through the Rich Text Editor, the unescaped HTML is rendered and the JavaScript executes in their browser context. The vulnerability requires an attacker to have the ability to set or control a username in a chat message. Patches are available in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.

## Affected products

- Discourse Discourse prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0

## Timeline

- 2026-08-10: disclosed
- 2026-01-06: patched: version 2026.1.6
- 2026-05-02: patched: version 2026.5.2
- 2026-06-01: patched: version 2026.6.1
- 2026-07-00: patched: version 2026.7.0

## References

- [https://github.com/discourse/discourse/commit/32920affe4ad97b461ca2ae2f664c5fefc374baf](https://github.com/discourse/discourse/commit/32920affe4ad97b461ca2ae2f664c5fefc374baf)
- [https://github.com/discourse/discourse/commit/3fb1e8ead0d4f48d2cf55c8110825c7e8a6a45f5](https://github.com/discourse/discourse/commit/3fb1e8ead0d4f48d2cf55c8110825c7e8a6a45f5)

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