XSS in Discourse

CVE-2026-72725

Discourse is an open-source discussion platform. Prior to 2026.1.6, the staff action log model rendered unescaped previous and new value fields that could inject stored cross-site scripting into the staff interface. The issue is fixed in 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 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (20.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 20.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-72725: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

  • Discourse — versions < 2026.1.6, >= 2026.5.0, < 2026.5.2, >= 2026.6.0, < 2026.6.1

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-72725?
CVE-2026-72725 is a medium-severity vulnerability in Discourse, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-08-10.
How severe is CVE-2026-72725?
Medium severity. CVSS v3 base score is 5.4 out of 10.