CVE-2025-66488
Discourse is an open source discussion platform. A vulnerability present in versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 affects anyone who uses S3 for uploads. While scripts may be executed, they will only be run in the context of the S3/CDN domain, with no site credentials. Versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 fix the issue. As a workaround, disallow html or xml files for uploads in authorized_extensions. For existing html xml uploads, site owners can consider deleting them.
| Software | From | Fixed in |
|---|---|---|
| discourse / discourse | - | 3.5.4 |
| discourse / discourse | 2025.11.0 | 2025.11.2 |
| discourse / discourse | 2025.12.0 | 2025.12.0.x |
| discourse / discourse | 2026.1.0 | 2026.1.0.x |
Deep Security Visibility Without the Complexity
SynScan provides clear, real-time security insights so you can monitor your attack surface, spot risks early, and act fast—without extra complexity.
- No setup fees
- 5-min deployment
- Cancel anytime