# N-Day Exploit **Entity class:** Vulnerability concept ## Definition An **n-day exploit** uses a vulnerability already known to defenders or vendors after public disclosure or patch availability. Success comes from incomplete mitigation, delayed deployment, weak configuration, fragmented ownership, or continued exposure. ## Relevance to this collection The Oklahoma City bombing is analogous at the institutional level: vehicle bombs were known, but federal-facility hardening had not propagated across the attack surface. ## Relationships - **master collection:** [[collections/Terrorism, Counterterrorism, and the Intelligence Environment|Terrorism, Counterterrorism, and the Intelligence Environment]]. - **convergence:** [[wiki/Counterterrorism-Cybersecurity Convergence|Counterterrorism–Cybersecurity Convergence]]. ## Sources / Provenance - [U.S. Government Accountability Office, *National Preparedness: Technologies to Secure Federal Buildings*, May 2, 2002](https://www.gao.gov/assets/a109302.html). **As of:** 2026-09-23