ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-28431

Misskey is an open source, federated social media platform.

Published Mar 10, 2026 · catalog updated Jun 17, 2026 · Misskey is an open

Check if you run it

No confirmed exploitation is on record for CVE-2026-28431. EPSS is 0.41%. Act only if a listed version of Misskey is an open is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Misskey is an open).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical9.2
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.41%
Remediation
Advisory link
Affected products
cpe misskey/misskey

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe misskey/misskeyversion unspecified

How to fix CVE-2026-28431

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-28431. EPSS is 0.41%. Act only if a listed version of Misskey is an open is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-285: Improper Authorization. EPSS 0.41%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 10, 2026 · NIST NVD

    Detected

    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 vu

  2. Jun 17, 2026 · NIST NVD

    Updated

    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 vu

Sources

  • CVE.orgVulnerability recordCVE-2026-28431

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-28431

    30-day exploitation probability 0.4%

    first.org
  • NIST NVDVulnerability recordCVE-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 to access due to insufficient permission c

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.