CVE-2026-69304: ASP.NET Core Denial of Service Vulnerability

mediumCVSS 5.9CVE-2026-69304

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

Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: medium — CVSS 5.9
Published: 2026-09-08
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69304

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-693040.77% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 53% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-69304	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for ASP.NET Core Denial

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

mediumGHSA-8cp2-47hg-mfgh: Microsoft Security Advisory CVE-2026-69304 – ASP.NET Core Denial of Service Vulnerabilityghsa · 2026-09-09
mediumGHSA-v3f6-m9j2-437p: Duplicate Advisory: Microsoft Security Advisory CVE-2026-69304 – ASP.NET Core Denial of S…ghsa · 2026-09-08
highCVE-2026-57099: ASP.NET Core Denial of Service Vulnerabilitymsrc · 2026-09-08
highCVE-2026-45646: OData for ASP.NET and ASP.NET Core Denial of Service Vulnerabilitymsrc · 2026-07-14
highCVE-2026-50506: OData for ASP.NET and ASP.NET Core Denial of Service Vulnerabilitymsrc · 2026-07-14
highCVE-2026-56170: ASP.NET Core Denial of Service Vulnerabilitymsrc · 2026-07-14