Medium 5.4Published Sep 21, 2026

CVE-2026-59830Discourse: Stored XSS via unescaped actor name in post actions

Updated under an hour ago (2026-10-19 09:10 UTC)

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It affects discourse. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

Discourse is an open-source discussion platform. Prior to 2026.7.0, the post action component failed to escape user-controlled display names before interpolating them into an HTML string passed to trustHTML. A user who could choose a crafted display name could persist markup in post action descriptions. Viewing the affected user activity streams could execute attacker-controlled script in another user's browser. This issue is fixed in version 2026.7.0.

CVSS: 5.4 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Weakness (CWE): CWE-79
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Sep 22, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

discourse discourse discourse:discourse (from the name)	before 2026.7.0	CNA record

References

https://github.com/discourse/discourse/security/advisories/GHSA-x6mf-p7cg-69rwx-refsource-confirm
https://github.com/discourse/discourse/commit/dd786594ddd088657a7e6f9fefba5bd889965fe4x-refsource-misc
https://github.com/discourse/discourse/releases/tag/v2026.7.0x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.