CVE-2026-69874

Think of Windows ALPC as an internal messaging system used by parts of Windows to talk to each other. This flaw is like a “trap door” where a local attacker who already has legitimate ability to run code can trigger the system to incorrectly use an unsafe pointer, leading to getting higher privileges. That can let an attacker do more than they should on the same machine.

This matters if you run Windows 10, Windows 11, or Windows Server 2019/2022/2025 on endpoints or servers where an attacker could already be “authorized” to run code (for example, through a compromised account or legitimate access). Because the weakness requires an attacker to already have a local foothold/ability to act on the machine, it is not primarily a remote-from-the-internet issue. Patch risk is highest on systems where untrusted or semi-trusted people/apps can run code locally (or where accounts may be compromised).

This is rated RED because it can turn a local, already-authorized attacker into a higher-privilege attacker on the machine. Even though there is no public exploit code on record and it is not listed in CISA KEV, the bug class (local privilege escalation) is exactly the kind attackers aim for after gaining initial access. Patch on a fast timeline for any affected hosts you cannot strongly restrict from local code execution by untrusted parties.