CVE-2025-25306Network attack vector

Federated note forgery via mismatched ActivityPub authority

Published Mar 10, 2025 · Updated Mar 12, 2025

Origin validation errors in Misskey 2025.2.0 and earlier allow remote attackers to forge federated notes through ActivityPub objects. Misskey accepts claimed authority from an object's url field without requiring matching authority in its id field for object types that bind authority to id. No authentication or user interaction is required; a malicious federated object can be accepted with false authorship, altering note integrity.

CVSS severity9.3
Critical
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Origin validation errors in Misskey 2025.2.0 and earlier allow remote attackers to forge federated notes through ActivityPub objects. Misskey accepts claimed authority from an object's url field without requiring matching authority in its id field for object types that bind authority to id. No authentication or user interaction is required; a malicious federated object can be accepted with false authorship, altering note integrity.

The record

CVE
CVE-2025-25306
Published
Mar 10, 2025
Updated
Mar 12, 2025
Vendor
Misskey Project
Product
Misskey
Classifications
CWE-346, CWE-1025, CWE-441, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 10, 2025CVE publishedPublication date reported by the CVE source.
  2. Mar 12, 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=< 2025.2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Misskey Project · Misskeyversion=< 2025.2.1

Published CVSS scores

9.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-346Origin Validation Error
CWE-1025Comparison Using Wrong Factors
CWE-441Unintended Proxy or Intermediary ('Confused Deputy')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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