CVE-2026-28432
Received Received - Intake
HTTP Signature Verification Bypass in Misskey Prior to

Publication date: 2026-03-10

Last updated on: 2026-03-13

Assigner: GitHub, Inc.

Description
Misskey 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.
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Meta Information
Published
2026-03-10
Last Modified
2026-03-13
Generated
2026-06-16
AI Q&A
2026-03-10
EPSS Evaluated
2026-06-15
NVD
CVE-2026-28432
EUVD
EUVD-2026-10367
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
misskey misskey to 2026.3.1 (exc)
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-347 The product does not verify, or incorrectly verifies, the cryptographic signature for data.
Attack-Flow Graph
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Executive Summary

CVE-2026-28432 is a high-severity vulnerability in Misskey, an open source federated social media platform. It allows attackers to bypass HTTP signature verification, which is a critical security mechanism used to authenticate requests. This flaw exists in all Misskey servers running versions prior to 2026.3.1 and affects all servers regardless of whether federation is enabled or disabled.

The vulnerability is due to improper verification of cryptographic signatures (CWE-347), where the product either fails to verify or incorrectly verifies HTTP signatures.

  • Affected Versions: All Misskey versions before 2026.3.1
  • Patched Version: 2026.3.1
  • Attack Vector: Network-based, allowing remote exploitation without physical access
  • Attack Complexity: Low
  • Privileges Required: null
  • User Interaction: null
Impact Analysis

This vulnerability allows attackers to bypass HTTP signature verification, compromising the integrity of requests made to Misskey servers.

Because attackers can forge or manipulate authenticated requests without needing any privileges or user interaction, this poses a significant risk to system integrity.

  • Confidentiality Impact: Low
  • Integrity Impact: High
  • Availability Impact: null

There are no known workarounds, so immediate upgrading to version 2026.3.1 is strongly recommended to mitigate this risk.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

The immediate step to mitigate this vulnerability is to upgrade all Misskey servers to version 2026.3.1 or later.

There are no available workarounds for this vulnerability, so applying the official patch is critical.

Upgrading will fix the improper verification of HTTP signatures and restore the integrity of authenticated requests.

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