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CVE-2026-69304 Microsoft CVE debrief

The ASP.NET Core Denial of Service Vulnerability is a highly compressed data handling issue in ASP.NET Core, allowing unauthorized attackers to cause service disruptions. Defenders responsible for .NET and ASP.NET Core deployments should assess exposure and apply patches or updates as necessary. This vulnerability has a CVSS score of 5.9, indicating a medium severity level. Affected product deployments should be identified in managed environments, and owners should be assigned for follow-up. Official advisories and CVE records should be reviewed to validate affected scope, severity, and vendor guidance.

Vendor
Microsoft
Product
ASP.NET Core
CVSS
MEDIUM 5.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-08
Original CVE updated
2026-10-08
Advisory published
2026-09-08
Advisory updated
2026-10-08

Who should care

Defenders responsible for .NET, ASP.NET Core, and Microsoft Visual Studio deployments should assess exposure and apply patches or updates as necessary.

Why it matters

The ASP.NET Core Denial of Service Vulnerability requires attention from defenders responsible for .NET and ASP.NET Core deployments. Patches or updates should be applied to prevent potential denial of service attacks. Inventory checks and verification of affected versions are necessary.

  • Denial of service attacks may occur against unpatched ASP.NET Core applications.
  • Verify and apply patches to prevent potential service disruptions.
  • Inventory checks are necessary to identify affected .NET and ASP.NET Core versions.
  • Remediation priority is medium due to the CVSS score of 5.9.

Technical summary

The ASP.NET Core Denial of Service Vulnerability occurs due to improper handling of highly compressed data, allowing an unauthorized attacker to deny service over a network. This issue affects .NET and ASP.NET Core deployments, and patches or updates should be applied to prevent potential denial of service attacks. The vulnerability has a medium defensive priority, and inventory checks are necessary to identify affected versions. Remediation involves updating to .NET 10.0.12, .NET 8.0.31, or .NET 9.0.20, or later versions, and verifying the applied patches.

Defensive priority

Medium

Recommended defensive actions

  • Review and apply patches from Microsoft for affected .NET and ASP.NET Core versions.
  • Update to .NET 10.0.12, .NET 8.0.31, or .NET 9.0.20, or later versions.
  • Update Microsoft Visual Studio to the latest versions.

Evidence notes

The CVE record and source item provide details on the ASP.NET Core Denial of Service Vulnerability. Microsoft has provided an advisory for this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-69304 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-69304

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-69304 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-69304

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • ASP.NET Core Denial of Service Vulnerability

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/69xxx/CVE-2026-69304.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

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

    Supplemental source - vendor-advisory, patch

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.