CVE-2026-28431 Details
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.
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Exploit prediction scoring system (EPSS) score for CVE-2026-28431
EPSS (Exploit Prediction Scoring System): EPSS predicts the likelihood that a vulnerability will be exploited in the wild. A higher percentage means a greater chance of an exploit occurring. The EPSS model produces a probability score between 0 and 1 (0 and 100%).
0.05 Probability of exploitation activity being observed over the next 30 days (15th percentile)
CVSS score for CVE-2026-28431
CVSS (Common Vulnerability Scoring System): An open framework owned and managed by FIRST.Org, Inc. that assigns a numerical score from 0 to 10 to software vulnerabilities to indicate their severity.
7.5 High
Products affected by CVE-2026-28431
Misskey 12.119.0
Misskey 12.119.2
Misskey 13.10.3
Misskey 13.13.2
Misskey 13.14.1
DVE Score by Bitsight AI
DVE scores complement traditional static scoring systems like CVSS with Bitsight AI powered real-time threat intelligence and underground cyber criminal activity so that security teams can reduce alert fatigue and focus on vulnerabilities most likely to be exploited.
Medium
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CVE-2026-28431 Global Footprint

Top 10 Identified Countries

Country Observations Percentage
JP 126 58.60%
US 33 15.35%
KR 10 4.65%
DE 8 3.72%
GB 6 2.79%
CN 5 2.33%
FR 5 2.33%
HK 5 2.33%
BR 3 1.40%
BG 2 0.93%

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CVE-2026-28431 Industry Footprint

Top 10 Identified Industries

*Service provider organizations (typically Technology and Telecommunications) are disproportionally represented in the results given their upstream ownership of end-user infrastructure. See our FAQs.

Industry* Observations Percentage
Technology 294 80.11%
Telecommunications 70 19.07%
Energy/Resources 2 0.54%
Utilities 1 0.27%

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