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Critical 9.2Published Mar 9, 2026

CVE-2026-28431Misskey lacks proper authorization checks and input validation

Updated under an hour ago ()

Does this affect you?

It affects misskey-dev misskey and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
9.2 CRITICAL (v4.0, CNA)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
Weakness (CWE)
CWE-285
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
GitHub_M
NVD analysis
Analyzed
Record last updated
Mar 10, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
misskey-dev misskey
misskey_dev:misskey (from the name)
from 8.45.0, < 2026.3.1
CNA record
misskey misskey
misskey:misskey
from 8.45.0 before 2026.3.1
NVD

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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