https://arstechnica.com/gadgets/2017/11/android-security-update-fixes-krack-slaps-band-aid-on-pixel-2-xl-screen/

It's a new month, and that means a new security update for Android. The November Android security patch is out, and this is more noteworthy than most with its fix for the high-profile key reinstallation attack (KRACK). It also puts some Band-Aids on the newly released Pixel 2 phones.

Google actually released three "November" security patches last night. First there's the normal "2017-11-01" security patch, which contains all the monthly patches developed on the regular schedule. OEMs get these fixes a full month in advance (so early October in this case), and Google lets the bugs sit around for a whole month, allowing OEMs to port the patch to their phones. A month later, Google discloses the bugs and (theoretically) does a simultaneous release with the Android OEMs and carriers.