CVE-2023-23624: Discourse

Medium severity, CVSS 5.3. EPSS: 0.6% chance of exploitation in the next 30 days.

Discourse is an open-source discussion platform. Prior to version 3.0.1 on the `stable` branch and version 3.1.0.beta2 on the `beta` and `tests-passed` branches, someone can use the `exclude_tag param` to filter out topics and deduce which ones were using a specific hidden tag. This affects any Discourse site using hidden tags in public categories. This issue is patched in version 3.0.1 on the `stable` branch and version 3.1.0.beta2 on the `beta` and `tests-passed` branches. As a workaround, secure any categories that are using hidden tags, change any existing hidden tags to not include private data, or remove any hidden tags currently in use.

Affected products

• Discourse Discourse: before 3.0.1 (fixed in 3.0.1); version 1.1.0 only; version 1.2.0 only; version 1.3.0 only; version 1.4.0 only; version 1.5.0 only; …

Published 2023-01-28. Last modified 2026-06-17.