XSS in Discourse
CVE-2026-72730
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (34.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002
Affected products
- Discourse — versions < 2026.1.6, >= 2026.5.0-latest, < 2026.5.2, >= 2026.6.0-latest, < 2026.6.1
Weakness classification (CWE)
References
- github.com/discourse/discourse/security/advisories/GHSA-wg48-qxjc-f459
- github.com/discourse/discourse/commit/32920affe4ad97b461ca2ae2f664c5fefc374baf
- github.com/discourse/discourse/commit/3fb1e8ead0d4f48d2cf55c8110825c7e8a6a45f5
- github.com/discourse/discourse/commit/7eb35d076ab9b6a612e86182336ce9787ce402ea
- github.com/discourse/discourse/commit/9633b8ecaf5a99f0407f5261b9bd1a05f7dac529
Frequently asked questions
- What is CVE-2026-72730?
- CVE-2026-72730 is a high-severity vulnerability in Discourse, classified under Cross-site Scripting. CVSS score: 8.7/10. Published 2026-08-10.
- How severe is CVE-2026-72730?
- High severity. CVSS v3 base score is 8.7 out of 10.