CVE-2024-25636Network attack vector

Remote account takeover via unchecked ActivityStreams media types

Published Feb 19, 2024 · Updated Aug 15, 2024

Improper media-type validation in Misskey before 2024.2.0 allows remote authenticated users to impersonate or take over remote accounts. ApResolverService.resolve parses fetched JSON as an ActivityStreams object without verifying an ActivityStreams Content-Type, and ApNoteService permits an intermediary Note to bypass the top-level ID refetch check. Exploitation requires an account on a remote server that hosts arbitrary uploads beside legitimate actors and returns those uploads for ActivityStreams requests, enabling actor spoofing and interception of private activities.

CVSS severity7.1
High
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper media-type validation in Misskey before 2024.2.0 allows remote authenticated users to impersonate or take over remote accounts. ApResolverService.resolve parses fetched JSON as an ActivityStreams object without verifying an ActivityStreams Content-Type, and ApNoteService permits an intermediary Note to bypass the top-level ID refetch check. Exploitation requires an account on a remote server that hosts arbitrary uploads beside legitimate actors and returns those uploads for ActivityStreams requests, enabling actor spoofing and interception of private activities.

The record

CVE
CVE-2024-25636
Published
Feb 19, 2024
Updated
Aug 15, 2024
Vendor
Misskey Project
Product
Misskey
Classifications
CWE-434, T1656
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 19, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2024Record 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=0 <2024.2.0
  2. Affected versionversion=< 2024.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Misskey Project · Misskeyversion=0 <2024.2.0; version=< 2024.2.0

Published CVSS scores

8.8NISTCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/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.

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-434Unrestricted Upload of File with Dangerous Type
T1656Impersonation

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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