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.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/mastodon/mastodon/commit/7e98fa9b476fdaed235519f1d527eb956004ba0c Patch
- https://github.com/mastodon/mastodon/security/advisories/GHSA-7gwh-mw97-qjgp Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 4.3 · joinmastodonNVD modified 2026-10-19 16:10
Affected (CPE criteria) 1
cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*