Microsoft Security Advisory CVE-2026-96958 - .NET and Visual Studio Denial of Service Vulnerability

[ Description ]Official description

Inefficient algorithmic complexity in .NET allows an unauthorized attacker to deny service over a network.

[ Fixes ]Fixes and patches

• System.Security.Cryptography.Xml 10.0.13Fixed version · GitHub Advisories · nuget package System.Security.Cryptography.Xml: upgrade to 10.0.13 or later (affected >= 10.0.0, <= 10.0.12)
• System.Security.Cryptography.Xml 11.0.0-rc.2Fixed version · GitHub Advisories · nuget package System.Security.Cryptography.Xml: upgrade to 11.0.0-rc.2 or later (affected >= 11.0.0-preview.1, <= 11.0.0-rc.1)
• System.Security.Cryptography.Xml 8.0.5Fixed version · GitHub Advisories · nuget package System.Security.Cryptography.Xml: upgrade to 8.0.5 or later (affected >= 8.0.0, <= 8.0.4)
• System.Security.Cryptography.Xml 9.0.21Fixed version · GitHub Advisories · nuget package System.Security.Cryptography.Xml: upgrade to 9.0.21 or later (affected >= 9.0.0, <= 9.0.20)

[ Advisories ]Government CERT advisories

• CERT-FR14 Oct 2026CERTFR-2026-AVI-1313

  Multiple vulnerabilities in Microsoft .Net Translated from French

  Multiple vulnerabilities have been discovered in Microsoft .Net. Some of them allow an attacker to cause remote arbitrary code execution, privilege escalation and remote denial of service.

  CVE-2026-70007CVE-2026-105016CVE-2026-96234+40 more CVEs
• CERT-FR14 Oct 2026CERTFR-2026-AVI-1316

  Multiple vulnerabilities in Microsoft products Translated from French

  Multiple vulnerabilities have been discovered in Microsoft products. Some of them allow an attacker to cause remote arbitrary code execution, privilege escalation and remote denial of service.

  CVE-2026-88086CVE-2026-70007CVE-2026-70179+141 more CVEs
• BSI CERT-Bund13 Oct 2026WID-SEC-2026-3893

  Microsoft Entwicklerwerkzeuge: Multiple vulnerabilities Translated from German

  Risk highCVE-2026-96230CVE-2026-84008CVE-2026-102238+64 more CVEs
• NCSC-NL13 Oct 2026NCSC-2026-0426

  Vulnerabilities fixed in Microsoft Developer Tools Translated from Dutch

  Probability/damage M/HCVE-2026-58280CVE-2026-66822CVE-2026-69370+59 more CVEs

[ Packages ]Affected open-source packages

• System.Security.Cryptography.Xml nugetAffected >= 10.0.0, <= 10.0.12 · fixed in 10.0.13 · GHSA-r955-8q5j-3h83
• System.Security.Cryptography.Xml nugetAffected >= 11.0.0-preview.1, <= 11.0.0-rc.1 · fixed in 11.0.0-rc.2 · GHSA-r955-8q5j-3h83
• System.Security.Cryptography.Xml nugetAffected >= 8.0.0, <= 8.0.4 · fixed in 8.0.5 · GHSA-r955-8q5j-3h83
• System.Security.Cryptography.Xml nugetAffected >= 9.0.0, <= 9.0.20 · fixed in 9.0.21 · GHSA-r955-8q5j-3h83

[ References ]References

• msrc.microsoft.com/update-guide/vulnerability/CVE-2026-96958Vendor Advisory