Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, a hostname validation issue in FinalDestination could allow bypassing SSRF protections under certain conditions. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. No known workarounds are available.
| 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 |