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.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
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
Which versions are affected by CVE-2025-62176?
1 open source package ship an affected version, including mastodon. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mastodon Bitnami | All versions | 4.2.27, 4.3.14, 4.4.6 |
Products include 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.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
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 Mastodon vulnerable to arbitrary file creation through media attachments
- CVE-2022-2166 Improper Restriction of Excessive Authentication Attempts in mastodon/mastodon
- CVE-2022-24307 Missing authorization in n/a
- CVE-2018-21018 Auth bypass in n/a
- CVE-2024-23832 Mastodon Remote user impersonation and takeover
Sources
Also known as BIT-mastodon-2025-62176, GHSA-7gwh-mw97-qjgp.