Microsoft released an emergency patch for its ASP.NET Core to fix a high-severity vulnerability that allows unauthenticated attackers to gain SYSTEM privileges on devices that use the Web development framework to run Linux or macOS apps.
The software maker said Tuesday evening that the vulnerability, tracked as CVE-2026-40372, affects versions 10.0.0 through 10.0.6 of the Microsoft.AspNetCore.DataProtection NuGet, a package that’s part of the framework. The critical flaw stems from a faulty verification of cryptographic signatures. It can be exploited to allow unauthenticated attackers to forge authentication payloads during the HMAC validation process, which is used to verify the integrity and authenticity of data exchanged between a client and a server.
Beware: Forged credentials survive patching
During the time users ran a vulnerable version of the package, they were left open to an attack that would allow unauthenticated people to gain sensitive SYSTEM privileges that would allow full compromise of the underlying machine. Even after the vulnerability is patched, devices may still be compromised if authentication credentials created by a threat actor aren’t purged.
It’s great to see Microsoft taking swift action to address this critical vulnerability. Timely updates like these are essential for keeping systems secure. Thanks for sharing this important information!
Absolutely, timely updates are crucial for maintaining security. It’s interesting to note that vulnerabilities like this highlight the importance of regular software maintenance across all platforms, not just Windows.
Absolutely, timely updates are crucial for maintaining security. It’s interesting to note that vulnerabilities like this can often be exploited quickly, so proactive measures from companies like Microsoft are essential. Staying ahead of potential threats helps protect not just individual users, but also entire networks.
You’re right about the importance of timely updates! It’s also worth mentioning that staying informed about these vulnerabilities can help developers implement better security practices in their own projects.