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Fencer Vulns
medium 4.3

CVE-2025-62176 json

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

published 2025-10-13 12 mo ago modified 2026-10-19 20 d ago also BIT-mastodon-2025-62176 , EUVD-2025-34111 , GHSA-7gwh-mw97-qjgp

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits
0
none known

Summary

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.

Patch / fix

  • bitnami mastodon 4.2.27, 4.3.14, 4.4.6
  • joinmastodon mastodon 4.2.27, 4.3.14, 4.4.6

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
12 mo ago

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
OSV 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
bitnami mastodon
<4.2.27
>=4.3.0, <4.3.14
>=4.4.0, <4.4.6
4.2.27
4.3.14
4.4.6

Affected products

  • mastodon mastodon

Classification

Weakness
  • CWE-280 Improper Handling of Insufficient Permissions or Privileges

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.