CVE-2025-62176

Mastadon streaming server allows OAuth clients without the `read` scope to subscribe to public channels

State
Published
Severity
4.3 Medium
Published
Oct 13, 2025
Updated
Oct 14, 2025
Reserved
Oct 7, 2025

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.14.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NGitHub_M

Weaknesses

  • CWE-280 Improper Handling of Insufficient Permissions or Privileges

Affected Products

ProductVersions
mastodonmastodon
  • >= 4.4.0-beta.1, < 4.4.6Affected
  • >= 4.3.0-beta.1, < 4.3.14Affected
  • < 4.2.27Affected

References

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