CVE-2025-62176Network attack vector

Authenticated public-post disclosure via skipped scope check

Published Oct 13, 2025 · Updated Oct 14, 2025

Authorization bypass in Mastodon streaming releases allows remote authenticated users to receive new public-timeline posts. The streaming server's checkScopes routine exempts public channels before checking whether a valid OAuth token grants read or read:statuses. A token lacking the required scope suffices in releases before 4.2.27, 4.3.14, or 4.4.6, and exposure is limited to newly published public posts, including those on limited-federation servers.

CVSS severity4.3
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in Mastodon streaming releases allows remote authenticated users to receive new public-timeline posts. The streaming server's checkScopes routine exempts public channels before checking whether a valid OAuth token grants read or read:statuses. A token lacking the required scope suffices in releases before 4.2.27, 4.3.14, or 4.4.6, and exposure is limited to newly published public posts, including those on limited-federation servers.

The record

CVE
CVE-2025-62176
Published
Oct 13, 2025
Updated
Oct 14, 2025
Vendor
Mastodon
Product
Mastodon
Classifications
CWE-280
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 13, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 14, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.2.27
  2. Affected versionversion=>= 4.3.0-beta.1, < 4.3.14
  3. Affected versionversion=>= 4.4.0-beta.1, < 4.4.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mastodon · Mastodonversion=< 4.2.27; version=>= 4.3.0-beta.1, < 4.3.14; version=>= 4.4.0-beta.1, < 4.4.6

Published CVSS scores

4.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-280Improper Handling of Insufficient Permissions or Privileges

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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