CVE-2023-23935 Information

Description

Discourse is an open-source messaging platform. In versions 3.0.1 and prior on the stable branch and versions 3.1.0.beta2 and prior on the beta and tests-passed branches the count of personal messages displayed for a tag is a count of all personal messages regardless of whether the personal message is visible to a given user. As a result any users can technically poll a sensitive tag to determine if a new personal message is created even if the user does not have access to the personal message. In the patched versions the count of personal messages tagged with a given tag is hidden by default. To revert to the old behaviour of displaying the count of personal messages for a given tag an admin may enable the display_personal_messages_tag_counts site setting.

Reference

https://github.com/discourse/discourse/commit/f31f0b70f82c43d93220ce6fc0d4f57440452f37 https://github.com/discourse/discourse/security/advisories/GHSA-rf8j-mf8c-82v7