CVE-2024-24817: User can see invitees in events created in PMs and private categories

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-02-22 · updated 2026-06-17
Weakness: CWE-200

Description

Discourse Calendar adds the ability to create a dynamic calendar in the first post of a topic on the open-source discussion platform Discourse. Prior to version 0.4, event invitees created in topics in private categories or PMs (private messages) can be retrieved by anyone, even if they're not logged in. This problem is resolved in version 0.4 of the discourse-calendar plugin. While no known workaround is available, putting the site behind `login_required` will disallow this endpoint to be used by anonymous users, but logged in users can still get the list of invitees in the private topics.

Affected products

discourse-calendar: before 0.4 — fixed in 0.4

How to fix

Upgrade to a fixed version: discourse-calendar 0.4. Check the vendor advisory for mitigations.

References

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