Is CVE-2026-59830 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-59830 being exploited in the wild.

How severe is CVE-2026-59830?

Medium severity, with a CVSS score of 5.4, published 21 September 2026.

Is there a fix for CVE-2026-59830?

A patch was published on 2026-07-28: fixed in version 2026.7.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-59830 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-59830?

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.

CVE-2026-59830: Discourse stored XSS via unescaped display name

CVE-2026-59830 · Severity: medium · CVSS 5.4 · Published 2026-09-21

Discourse is an open-source community discussion platform where users can post and interact. An attacker could craft a malicious display name that would inject JavaScript code into post action descriptions, allowing the attacker to steal session tokens, deface posts, or perform actions on behalf of any user viewing that user's activity stream.

Technologies: Discourse. Vendors: Discourse.

Quick answers

Is CVE-2026-59830 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-59830 being exploited in the wild.
How severe is CVE-2026-59830?: Medium severity, with a CVSS score of 5.4, published 21 September 2026.
Which products and versions are affected?: Discourse before 2026.7.0.
Is there a fix for CVE-2026-59830?: A patch was published on 2026-07-28: fixed in version 2026.7.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-59830 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-59830?: 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

Stored XSS vulnerability in the post-action-description component where user-controlled display names are interpolated into HTML passed to trustHTML without proper escaping. An authenticated attacker can set a crafted display name containing HTML/JavaScript markup; when other users view the attacker's activity stream or post actions, the malicious script executes in their browser context. Fixed in version 2026.7.0.

Affected products

Discourse Discourse before 2026.7.0

Timeline

2026-09-21: disclosed
2026-07-28: patched: fixed in version 2026.7.0

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.