What is CVE-2026-28431?

CVE-2026-28431 is a high-severity vulnerability in Misskey, classified under Improper Authorization. CVSS score: 7.5/10. Published 2026-03-10.

How severe is CVE-2026-28431?

High severity. CVSS v3 base score is 7.5 out of 10.

Auth bypass in Misskey

CVE-2026-28431

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 t…

EPSS: 0.002 (16.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

Affected products

Misskey
Misskey-dev Misskey — versions >= 8.45.0, < 2026.3.1

Weakness classification (CWE)

CWE-285 — Improper Authorization

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2026-28431?: CVE-2026-28431 is a high-severity vulnerability in Misskey, classified under Improper Authorization. CVSS score: 7.5/10. Published 2026-03-10.
How severe is CVE-2026-28431?: High severity. CVSS v3 base score is 7.5 out of 10.