High severity8.8NVD Advisory· Published May 12, 2026· Updated May 15, 2026
CVE-2026-40403
CVE-2026-40403
Description
Heap-based buffer overflow in Windows Win32K - GRFX allows an authorized attacker to execute code locally.
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
1- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40403nvdVendor Advisory
News mentions
4- Patch Tuesday - May 2026Rapid7 Blog · May 13, 2026
- Microsoft Patch Tuesday for May 2026 — Snort rules and prominent vulnerabilitiesCisco Talos Intelligence · May 12, 2026
- Microsoft May 2026 Patch Tuesday fixes 120 flaws, no zero-daysBleepingComputer · May 12, 2026
- May 2026 Patch Tuesday: 30 Critical Vulnerabilities Among 130 CVEsCrowdStrike Blog