🛡️ Security

Time-of-Check to Time-of-Use (TOCTOU)

A class of race-condition flaw where a program validates a resource, then acts on it a moment later, and an attacker changes the resource in the gap between the two steps. Link-following privilege-escalation bugs such as CVE-2026-81963 exploit this window.

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How Link-Following Bugs Turn Privileged File Operations Into SYSTEM Access

A link-following bug lets a low-privileged attacker redirect a trusted service's file operation to a target they choose. That is how CVE-2026-81963 reached SYSTEM on Windows.

intermediate 5 min read

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