CVE-2025-46824 is a cross-site scripting (XSS) vulnerability identified in the discourse-code-review plugin, which is an extension for the Discourse platform enabling users to review GitHub commits directly within Discourse forums. The vulnerability arises from improper neutralization of input during web page generation (CWE-79). Specifically, prior to the patch introduced in commit eed3a80, an attacker could craft malicious links to GitHub commits that, when posted in the Discourse environment using the vulnerable plugin, would execute arbitrary JavaScript code in the browsers of users viewing those posts. This type of vulnerability allows attackers to perform actions such as session hijacking, defacement, or redirecting users to malicious sites without requiring user interaction or elevated privileges. The vulnerability affects all versions of the discourse-code-review plugin before commit eed3a80. The CVSS v3.1 base score is 3.1, indicating a low severity primarily due to the high attack complexity and the requirement for at least low privileges (authenticated user) to exploit, with no user interaction needed. The vulnerability does not impact integrity or availability but has a limited confidentiality impact. No known exploits are currently observed in the wild. The recommended remediation is to update the discourse-code-review plugin to the fixed version at commit eed3a80 or later. As a temporary workaround, disabling the plugin entirely can mitigate the risk.

For European organizations using Discourse forums with the discourse-code-review plugin, this vulnerability poses a risk of client-side script execution leading to potential session hijacking or unauthorized actions within the forum context. While the direct impact is limited due to the low CVSS score, organizations with active developer communities or internal collaboration platforms using this plugin could face targeted phishing or social engineering attacks leveraging this XSS flaw. Confidential information accessible via user sessions could be exposed, and trust in internal communication platforms could be undermined. The impact is more pronounced in organizations where sensitive code reviews or proprietary information are shared via Discourse. However, since exploitation requires at least low-level authenticated access and has high attack complexity, the threat is somewhat contained. Nonetheless, European entities with compliance obligations around data protection (e.g., GDPR) should consider the confidentiality implications seriously.

1. Immediate upgrade of the discourse-code-review plugin to the patched version at commit eed3a80 or later is the primary mitigation step. 2. If upgrading is not immediately feasible, disable the discourse-code-review plugin to prevent exploitation. 3. Implement strict Content Security Policy (CSP) headers on Discourse instances to limit the execution of unauthorized scripts. 4. Conduct regular security audits and code reviews of plugins and extensions used within Discourse to identify similar vulnerabilities proactively. 5. Educate users about the risks of clicking on suspicious links within forums, especially those related to code reviews. 6. Monitor forum logs for unusual activity or repeated posting of suspicious GitHub commit links. 7. Ensure that Discourse and its plugins are kept up to date with security patches as part of routine maintenance.