CVE-2026-28432
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 · uneditedMisskey is an open source, federated social media platform. All Misskey servers prior to 2026.3.1 contain a vulnerability that allows bypassing HTTP signature verification. Although this is a vulnerability related to federation, it affects all servers regardless of whether federation is enabled or disabled. This vulnerability is fixed in 2026.3.1.
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 confidenceMisskey versions prior to 2026.3.1 contain a vulnerability that allows attackers to bypass HTTP signature verification. This flaw enables spoofing of federation requests between servers, potentially allowing injection of malicious content or unauthorized actions, and affects all installations regardless of federation settings.
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< 2026.3.1CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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 checksWork through these to decide whether this CVE applies to you.
-
Check Misskey version via package.jsonLocate and read the package.json file in the Misskey installation directory. Look for the 'version' field.Affected if The version number is lower than 2026.3.1 (for example, 2026.3.0, 2026.2.x, or any earlier release).
-
Check Misskey version via admin panelLog into the Misskey admin dashboard and navigate to the About or Settings section to view the installed version.Affected if The displayed version is below 2026.3.1.
-
Check Misskey version via API endpointSend a GET request to the instance API (for example, /api/v1/instance or /api/meta) and examine the 'version' or 'misskey_version' field in the response.Affected if The returned version string indicates a release earlier than 2026.3.1.
-
Verify version via git or changelogIf the source code is deployed, check the git tags or CHANGELOG.md file in the repository for the current version tag.Affected if The tagged version is prior to the 2026.3.1 release tag.
If the installed Misskey version is anything below 2026.3.1, the environment is affected by this HTTP signature verification bypass vulnerability regardless of federation configuration.
Generated from the published advisory. Verify against your own configuration.
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 · scoped2026.3.1
Upgrade Misskey to version 2026.3.1 or later to remediate this vulnerability. This is a critical security update that should be prioritized given the CVSS 7.5 severity.
2026.3.1
- Verify current Misskey version to confirm vulnerability exposure
- Consult Misskey official documentation or release notes for upgrade instructions specific to your deployment method
- Backup database and configuration files before upgrading
- Upgrade to Misskey version 2026.3.1 or later
- Verify the upgrade was successful and the server is operational
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-28432 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-28432 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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