# CVE-2021-41082: Private message title and participating users leaked in discourse

> Attackers can view titles and participants of private messages involving groups, leaking metadata without accessing message content.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Sep 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-vm3x-w6jm-j9vv

## What is CVE-2021-41082?

CVE-2021-41082 is a high-severity vulnerability in Discourse Discourse, published on 20 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Discourse is a platform for community discussion. In affected versions any private message that includes a group had its title and participating user exposed to users that do not have access to the private messages. However, access control for the private messages was not compromised as users were not able to view the posts in the leaked private message despite seeing it in their inbox. The problematic commit was reverted around 32 minutes after it was made. Users are encouraged to upgrade to the latest commit if they are running Discourse against the `tests-passed` branch.

Weakness: CWE-863 (Incorrect Authorization), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2021-41082?

It affects 1 product.


Products: Discourse Discourse.

## How do I fix CVE-2021-41082?

No fix has been published for CVE-2021-41082 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-41082 being exploited?

There is no known exploitation of CVE-2021-41082 in the wild and no public exploit code.

## Other vulnerabilities in Discourse Discourse

- [CVE-2021-41163](https://insights.sbomify.com/CVE-2021-41163/): RCE via malicious SNS subscription payload (critical 10.0)
- [CVE-2022-36066](https://insights.sbomify.com/CVE-2022-36066/): Discourse vulnerable to RCE via admins uploading maliciously zipped file (critical 9.1)
- [CVE-2022-39356](https://insights.sbomify.com/CVE-2022-39356/): Discourse user account takeover via email and invite link (high 8.9)
- [CVE-2023-22468](https://insights.sbomify.com/CVE-2023-22468/): Discourse vulnerable to Cross-site Scripting in local oneboxes (high 8.8)
- [CVE-2026-27934](https://insights.sbomify.com/CVE-2026-27934/): Discourse leaks private topic title and post excerpt via user action API endpoint (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-41082 and fix it if it is affected.

What it is: CVE-2021-41082 is a high-severity vulnerability in Discourse Discourse, published on 20 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-41082 in the wild and no public exploit code.

Affected product: Discourse Discourse. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-41082/ (Markdown: https://insights.sbomify.com/CVE-2021-41082/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-41082
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-41082
- OSV: https://osv.dev/vulnerability/CVE-2021-41082

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-41082/
Summaries are generated and may contain mistakes; the official description above is the record.