CVE-2026-33411: Discourse's solved topic stream has potential stored XSS in topic title

Published Mar 20, 2026
·
Updated

Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 have a potential stored XSS in topic titles for the solved posts stream. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, ensure that the Content Security Policy is enabled, and has not been modified in a way which would make it more vulnerable to XSS attacks.

Affected Software

4 affected components
Discourse Discourse<2026.3.0-latest.1, <2026.2.1, <2026.1.2
Discourse Discourse>=2026.1.0<2026.1.2
Discourse Discourse>=2026.2.0<2026.2.1
Discourse Discourse=2026.3.0

Event History

Mar 20, 2026
CVE Published
via MITRE·10:58 PM
Data Sourced
via MITRE·10:58 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·11:16 PM
DescriptionSeverityWeaknessAffected Software
Dec 26, 58199
Event
via FIRST·08:53 AM

Frequently Asked Questions

1

What is the severity of CVE-2026-33411?

CVE-2026-33411 is classified as a potential stored XSS vulnerability that could impact the security of affected Discourse installations.

2

How do I fix CVE-2026-33411?

To mitigate CVE-2026-33411, upgrade to Discourse versions 2026.3.0-latest.1, 2026.2.1, or 2026.1.2.

3

What versions are affected by CVE-2026-33411?

Discourse versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 are affected by CVE-2026-33411.

4

What are the potential impacts of CVE-2026-33411?

The potential impact of CVE-2026-33411 includes the risk of stored cross-site scripting attacks that could compromise user data.

5

Is CVE-2026-33411 a remote vulnerability?

CVE-2026-33411 can be exploited remotely if an attacker can craft malicious topic titles in the Discourse platform.

Contact

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