CVE-2026-28431

critical · 9.2

Misskey 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 vulnerability that allows bad actors access to data that they ordinarily wouldn't be able to access due to insufficient permission checks and proper input validation. This vulnerability occurs regardless of whether federation is enabled or not. This vulnerability could lead to a significant data breach. This vulnerability is fixed in 2026.3.1.

9.2

CVSS

0.2%

EPSS (exploit prob.)

17th

EPSS percentile

2026-03-10

Published

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/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:X/V:X/RE:X/U:X

Weaknesses

CWE-285

Affected products

Vendor	Product	Affected versions
misskey	misskey	>= 8.45.0, < 2026.3.1

Check a specific version with /api/v1/cve/match.

References

https://github.com/misskey-dev/misskey/security/advisories/GHSA-r33c-qg3g-v9cr

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-28431