SB2026041580 - Multiple vulnerabilities in Microsoft .NET Framework

Description

This security bulletin contains information about 2 vulnerabilities.

1) Improper handling of exceptional conditions (CVE-ID: CVE-2026-23666)

CWE-ID: CWE-755 - Improper Handling of Exceptional Conditions

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Green

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper handling of errors in .NET Framework. A remote attacker can send specially crafted input and perform a denial of service (DoS) attack.

2) Race condition (CVE-ID: CVE-2026-32226)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a race condition in .NET Framework. A remote attacker can exploit the race and cause a denial of service condition on the system.

Remediation

Install update from vendor's website.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-23666
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-32226