Microsoft’s September 2026 Patch Tuesday addresses 964 CVEs, including 104 rated Critical and 860 rated Important, making it the company’s largest Patch Tuesday release on record.
Microsoft lists 974 CVEs in its full September security release. However, 10 of those affect cloud services or involve fixes that Microsoft applies itself, leaving 964 vulnerabilities that customers need to patch.
The release includes fixes for two actively exploited Windows zero-days. Both are local elevation-of-privilege vulnerabilities that could allow an attacker who already has access to a device to gain SYSTEM privileges. Neither provides remote access by itself, but SYSTEM-level access is valuable to malware operators after they gain an initial foothold through phishing, stolen credentials, or another method.
How to apply patches and check if you’re protected
These updates fix security problems and help keep your Windows PC protected. Here’s how to make sure you’re up to date:
