New to this? Read it in simple words
- Microsoft fixed more than 1,400 security holes in its October updates, its most ever.
- The record before was September, with nearly 1,000 fixes.
- One Windows flaw was already being used by attackers.
- Microsoft says AI-assisted research is helping people find more bugs.
- Vulnerability
- A weakness in software that an attacker could use to get in or cause harm.
- Zero-day
- A flaw that attackers know about or use before a fix is ready.
- Patch
- A software update that fixes a flaw.
On the second Tuesday of each month, Microsoft releases fixes for security holes in its software. The October batch is the biggest it has ever released.
A record month
Microsoft’s updates of October 13 fix more than 1,400 vulnerabilities. Outlets count the total slightly differently, but all agree that it is a record.
The previous record was September, with nearly 1,000 fixes. Krebs on Security says that was already about ten times a normal month.
Dozens of the October flaws are rated critical, the highest level.
Microsoft’s October 13 updates; outlets count the total slightly differently, all above 1,400.
Where AI comes in
“As AI-assisted research contributes to vulnerability discovery, this kind of approach may become more useful,” Microsoft wrote about a new way to sort its fixes.
Krebs on Security reports that Microsoft credits large language models for the rise. SecurityWeek calls the growth “driven by AI”.
The new “risk cohorts” put the fixes into 15 example groups, to help IT teams decide what to install first. Microsoft says the groups are provisional and don’t change its advice.
A zero-day already in use
One flaw, CVE-2026-96951 in the Windows Shell, was already being used by attackers, Microsoft says. It lets attackers get around Mark of the Web, the label Windows puts on files from the internet so it can warn people.
Microsoft credits four finders for it. One of them is listed as “Benoit Sevens using Claude with Anthropic”, and two work for Fujitsu.
Windows 11 version 24H2 Home and Pro got their last security update this month, BleepingComputer reports, quoting Microsoft.
Sources
Every fact in this story comes from the sources below. Open them to check our work.
- 1
- 2Primary source · October 13, 2026Using risk cohorts to prioritize security updates Microsoft Security Response Center
- 3
- 4Research · October 13, 2026Microsoft October 2026 Patch Tuesday fixes 1,411 flaws, 3 zero-days BleepingComputer
- 5Research · October 14, 2026Microsoft Patches Record 1,413 Vulnerabilities, Including Exploited Windows Zero-Day SecurityWeek
- 6
The flaws and their finders come from Microsoft’s own data. That AI drives the rise is Microsoft’s and reporters’ view, and outlets count the total slightly differently.
Over 1,400 security holes and a Windows flaw already used by attackers outweigh the good news that fixes are out. How we rate the mood