dbcve.org
MisskeyApplication

CVE-2023-25154

MEDIUM · 6.1 CVSS v3.1 Published 2023-02-22
Fix available
A fix is available. Upgrade to 13.5.0 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Misskey is an open source, decentralized social media platform. In versions prior to 13.5.0 the link to the instance to the sender that appears when viewing a user or note received through ActivityPub is not properly validated, so by inserting a URL with a javascript scheme an attacker may execute JavaScript code in the context of the recipient. This issue has been fixed in version 13.5.0. Users are advised to upgrade. Users unable to upgrade should not "view on remote" for untrusted instances.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Misskey versions before 13.5.0 contain a stored XSS vulnerability in ActivityPub handling. When users view remote notes or profiles via ActivityPub, the instance link back to the sender is not properly validated, allowing attackers to inject javascript: scheme URLs that execute arbitrary JavaScript in the victim's browser context.

MitigationUpgrade to Misskey version 13.5.0 or later which includes proper URL validation. Until upgraded, avoid using the 'view on remote' feature for untrusted instances.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
MisskeyApplication
Affected:< 13.5.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Misskey version
    Locate the Misskey version by accessing the admin dashboard 'About' page, checking the package.json file in the Misskey installation directory, or querying the Misskey API endpoint /api/meta (requires auth). Compare the version number to the affected range (anything below 13.5.0).
    Affected if The installed version is below 13.5.0
  2. Verify ActivityPub module is enabled
    Check the Misskey configuration file (default.yml or config.yml) for the 'activitypub' setting, or access the admin settings panel to confirm the ActivityPub module is active. This feature handles federation with remote instances.
    Affected if ActivityPub is enabled and the instance federates with remote servers
  3. Confirm remote note/profile viewing is accessible
    Test whether users can view remote notes or profiles via the 'view on remote' link by attempting to access a federated note from another instance. This is typically accessible through the note context menu or profile page links.
    Affected if Users can click through to view content on remote instances from your server
  4. Inspect ActivityPub endpoint responses
    Examine the JSON responses from your instance's ActivityPub endpoints (typically /@username or /notes/:id in ActivityPub format). Look for any 'url' fields in note objects or actor objects that may contain javascript: scheme URLs when processed by your instance.
    Affected if Your instance processes and displays ActivityPub content from untrusted remote instances

Your instance is affected if it runs a Misskey version below 13.5.0, has ActivityPub enabled for federation, and users can view remote content through the 'view on remote' feature, allowing javascript: URL injection from malicious remote instances.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 13.5.0 or later
Fixed in 13.5.0
Interim mitigation

Upgrade to Misskey version 13.5.0 or later which includes proper URL validation. Until upgraded, avoid using the 'view on remote' feature for untrusted instances.

Recommended fix High confidence

13.5.0

  1. Back up your Misskey instance data and database before upgrading
  2. Update or upgrade your Misskey installation to version 13.5.0
  3. Restart the Misskey service to apply the changes
  4. Verify the upgrade was successful by checking the version

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Misskey Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-25154 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data