Microsoft Security Response CenterCVE-2026-66822

.NET Information Disclosure Vulnerability

HighVendor CVSS 5.9 / 10 1 CVE Published Oct 13, 2026 at 7:00 AM UTC

Summary

Insertion of sensitive information into sent data in .NET allows an unauthorized attacker to disclose information over a network.

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Release Notes Install KB5130036. Install KB5130034. Install KB5130035.

Update history

SecurityAlert records field-level changes from the point we begin following a bulletin. Earlier vendor changes may not have a field-by-field record.

Oct 15, 2026 at 11:35 PM UTC
- The vendor changed the advisory's last-updated date.

Oct 13, 2026 at 7:00 AM UTC
Published by Microsoft Security Response Center
The publication date reported by the vendor.
Oct 13, 2026 at 10:55 PM UTC
Added to SecurityAlert
We collected the advisory from the official source.
Oct 15, 2026 at 7:00 AM UTC
Updated by Microsoft Security Response Center
The vendor changed the advisory after it was first published.
Oct 21, 2026 at 1:15 AM UTC
Confirmed at the source
Our collector saw this advisory during a later source check.

Details collected from Microsoft Security Response Center.

Official bulletin How SecurityAlert builds this record

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