← Vulnerability feed

Vulnerability record · CVE-2026-28432 · published 10 March 2026

CVE-2026-28432: Misskey improper verification of cryptographic signature vulnerability

Misskey · Misskey

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.

7.1 CVSS 4.0 High EPSS 0.24% · top 86.3% CWE-347 · Improper verification of cryptographic signature
7.1CVSS 4.0 base score
0.24%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
1References
17 Jun 2026Last modified by NVD

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.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/misskey-dev/misskey/security/advisories/GHSA-grwc-c762-gcvp Vendor Advisory

Track CVE-2026-28432 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2023-24812Misskey sql injection vulnerabilityMisskey is an open source, decentralized social media platform. In versions prior to 13.3.3 SQL injection is possible due to insufficient parameter v…EPSS 0.71%9.6CVE-2023-52139Misskey improper authorization vulnerabilityMisskey is an open source, decentralized social media platform. Third-party applications may be able to access some endpoints or Websocket APIs that …EPSS 0.55%9.3CVE-2025-25306Misskey origin validation error vulnerabilityMisskey is an open source, federated social media platform. The patch for CVE-2024-52591 did not sufficiently validate the relation between the `id` …EPSS 0.18%9.2CVE-2026-28431Misskey improper authorization vulnerabilityMisskey is an open source, federated social media platform. All Misskey servers running versions 8.45.0 and later, but prior to 2026.3.1, contain a v…EPSS 0.39%8.8CVE-2024-52590Misskey improper input validation vulnerabilityMisskey is an open source, federated social media platform. In affected versions missing validation in `ApRequestService.signedGet` allows an attacke…EPSS 0.35%8.8CVE-2024-52591Misskey improper input validation vulnerabilityMisskey is an open source, federated social media platform. In affected versions missing validation in `ApRequestService.signedGet` and `HttpRequestS…EPSS 0.32%8.8CVE-2024-25636Misskey unrestricted file upload vulnerabilityMisskey is an open source, decentralized social media platform with ActivityPub support. Prior to version 2024.2.0, when fetching remote Activity Str…EPSS 0.66%8.2CVE-2025-24897Misskey cross-site request forgery vulnerabilityMisskey is an open source, federated social media platform. Starting in version 12.109.0 and prior to version 2025.2.0-alpha.0, due to a lack of CSRF…EPSS 0.14%

Source: NIST National Vulnerability Database (record CVE-2026-28432), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.