KB5082142: Windows Server 2022 Security Update (April 2026)

An attacker chains this bypass with another vector — a phishing attachment, a malicious download, or an existing foothold — to evade the protection the bypassed feature provides. In practice that means getting attacker-controlled content past a check that would normally warn the user or block execution (e.g., suppressing a Mark-of-the-Web warning so a downloaded file runs without the usual prompt).

The Windows Shell is the component that handles file associations, shortcuts, URI handlers, and the enforcement of several security policies (Mark-of-the-Web, application control, UAC prompts). A flaw lets an attacker bypass a network security feature the Shell is supposed to enforce — typically by exploiting inconsistencies between how a security policy is defined and how the Shell interprets it.

Probably yes if any of these apply:

An attacker sends a phishing email with an attachment that would normally trigger a Mark-of-the-Web "this file came from the internet" warning. Exploiting the Shell bypass, the file opens without the warning, and the user runs it believing it is safe. Shell and Mark-of-the-Web bypasses appear in CISA KEV listings regularly because they are the first step that turns a phishing email into code execution.