CVE-2026-69304: Microsoft .net

Medium severity, CVSS 5.9. EPSS: 0.9% chance of exploitation in the next 30 days.

Improper handling of highly compressed data (data amplification) in ASP.NET Core allows an unauthorized attacker to deny service over a network.

Affected products

• Microsoft .net: from 8.0.0, before 8.0.31 (fixed in 8.0.31); from 9.0.0, before 9.0.20 (fixed in 9.0.20); from 10.0.0, before 10.0.12 (fixed in 10.0.12)
• Microsoft ASP.NET Core: from 8.0.0, before 8.0.28 (fixed in 8.0.28); from 9.0.0, before 9.0.17 (fixed in 9.0.17); from 10.0.0, before 10.0.9 (fixed in 10.0.9); after 11.0.0; version 11.0 only
• Microsoft Visual Studio 2022: from 17.14.0, before 17.14.40 (fixed in 17.14.40)
• Microsoft Visual Studio 2026: from 18.9.0, before 18.9.3 (fixed in 18.9.3)

Published 2026-09-08. Last modified 2026-09-30.