CVE-2026-32243
Cross-Site Scripting in Discourse AI Conversation Titles
Publication date: 2026-03-31
Last updated on: 2026-04-09
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| discourse | discourse | 2026.3.0 |
| discourse | discourse | From 2026.1.0 (inc) to 2026.1.3 (exc) |
| discourse | discourse | From 2026.2.0 (inc) to 2026.2.2 (exc) |
| discourse | discourse | 2026.3.0 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-79 | The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
CVE-2026-32243 is a stored Cross-Site Scripting (XSS) vulnerability in the Discourse AI shared conversations onebox feature. An attacker who can create shared AI conversations can inject arbitrary HTML and JavaScript code through specially crafted conversation titles.
This malicious code executes in the browsers of users viewing the onebox preview, potentially allowing the attacker to hijack user sessions or perform unauthorized actions on behalf of the victim.
The vulnerability affects Discourse versions from 2026.1.0 up to but not including 2026.1.3, 2026.2.0 up to but not including 2026.2.2, and 2026.3.0 up to but not including 2026.3.0, and has been patched in later versions.
How can this vulnerability impact me? :
This vulnerability can impact you by allowing attackers to execute malicious scripts in your browser when you view shared AI conversation previews in Discourse.
Such script execution can lead to session hijacking, where attackers steal your session tokens to impersonate you.
Additionally, attackers could perform unauthorized actions on your behalf within the Discourse platform, potentially compromising your account and data.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability involves stored Cross-Site Scripting (XSS) via crafted conversation titles in Discourse AI shared conversations. Detection would involve identifying AI conversation titles containing unescaped or suspicious HTML or JavaScript payloads.
Since the vulnerability manifests when viewing the onebox preview of shared AI conversations, you can detect it by inspecting the HTML content of these previews for unescaped or malicious scripts.
No specific detection commands are provided in the available resources.
What immediate steps should I take to mitigate this vulnerability?
The recommended immediate mitigation is to update Discourse to one of the patched versions: 2026.1.3, 2026.2.2, or 2026.3.0.
These updates include a fix that properly escapes HTML content in AI conversation titles before rendering, preventing the execution of malicious scripts.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
This vulnerability allows an attacker to inject arbitrary HTML and JavaScript that executes in the browsers of users viewing the affected feature, potentially enabling session hijacking or unauthorized actions on behalf of the victim.
Such unauthorized access and potential compromise of user sessions could lead to violations of data protection and privacy requirements found in common standards and regulations like GDPR and HIPAA, which mandate the protection of personal data and secure user authentication.
Therefore, if exploited, this vulnerability could negatively impact compliance by exposing user data or enabling unauthorized actions, which are typically prohibited under these regulations.
The issue has been patched in later versions, and updating to these versions is recommended to maintain compliance and security.