# CVE-2025-62176: Mastadon streaming server allows OAuth clients without the `read` scope to subscribe to public channels

> OAuth clients lacking read scope can subscribe to public timelines, allowing unauthorized access to public posts.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Oct 2025
- **Updated:** 14 Oct 2025
- **Also known as:** BIT-mastodon-2025-62176, GHSA-7gwh-mw97-qjgp

## What is CVE-2025-62176?

CVE-2025-62176 is a medium-severity missing authorization vulnerability in mastodon, published on 13 Oct 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Mastodon is a free, open-source social network server based on ActivityPub. In Mastodon before 4.4.6, 4.3.14, and 4.2.27, the streaming server accepts serving events for public timelines to clients using any valid authentication token, even if those tokens lack the read:statuses scope. This allows OAuth clients without the read scope to subscribe to public channels and receive public timeline events. The impact is limited, as this only affects new public posts published on the public timelines and requires an otherwise valid token, but this may lead to unexpected access to public posts in a limited-federation setting. This issue has been patched in versions 4.4.6, 4.3.14, and 4.2.27. No known workarounds exist.

Weakness: CWE-280 (Improper Handling of Insufficient Permissions or Privileges)

## Which versions are affected by CVE-2025-62176?

1 open source package ship an affected version, including mastodon. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mastodon` | Bitnami | All versions | 4.2.27, 4.3.14, 4.4.6 |

Products: Joinmastodon Mastodon.

## How do I fix CVE-2025-62176?

Upgrade mastodon to a fixed version for your release line: 4.2.27, 4.3.14 or 4.4.6.

## Is CVE-2025-62176 being exploited?

There is no known exploitation of CVE-2025-62176 in the wild and no public exploit code.

## Other vulnerabilities in mastodon

- [CVE-2023-36460](https://insights.sbomify.com/CVE-2023-36460/): Mastodon vulnerable to arbitrary file creation through media attachments (critical 10.0)
- [CVE-2022-2166](https://insights.sbomify.com/CVE-2022-2166/): Improper Restriction of Excessive Authentication Attempts in mastodon/mastodon (critical 9.8)
- [CVE-2022-24307](https://insights.sbomify.com/CVE-2022-24307/): Missing authorization in n/a (critical 9.8)
- [CVE-2018-21018](https://insights.sbomify.com/CVE-2018-21018/): Auth bypass in n/a (critical 9.8)
- [CVE-2024-23832](https://insights.sbomify.com/CVE-2024-23832/): Mastodon Remote user impersonation and takeover (critical 9.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-62176 and fix it if it is affected.

What it is: CVE-2025-62176 is a medium-severity missing authorization vulnerability in mastodon, published on 13 Oct 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-62176 in the wild and no public exploit code.

Affected packages and fixed versions:
- mastodon (Bitnami): affected all versions; fixed in 4.2.27, 4.3.14, 4.4.6

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-2025-62176/ (Markdown: https://insights.sbomify.com/CVE-2025-62176/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-62176
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-62176
- OSV: https://osv.dev/vulnerability/CVE-2025-62176

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-62176/
Summaries are generated and may contain mistakes; the official description above is the record.