Microsoft has released cumulative update KB5120240 for Windows 11 version 23H2 (2023 Update) as part of the August 2026 Patch Tuesday. The system build increases to 22631.7517. Please note that support for Windows 11 version 23H2 in the Home and Pro editions ended on November 11, 2025, so these editions no longer receive monthly security updates automatically. Microsoft strongly recommends upgrading to Windows 11 version 25H2.
- Secure Boot. New data has been added for more accurate targeting of devices, which has increased the coverage of computers ready to automatically receive new Secure Boot certificates. In the coming months, their phased rollout through Windows Update will continue on supported PCs and unmanaged corporate devices.
- Connectivity. The COSA profile for the SolNet-Mobile operator has been updated — support for the latest mobile operator settings has been added.
- Device Management. The reliability of MDM-managed devices has been improved: they now continue to function normally even after the MDM certificate expires.
- File History. The reliability of File History backup to network folders via the SMB protocol has been enhanced. Scheduled tasks should now correctly access network locations and copy files.
- Emoji Panel. The emoji panel, invoked by the Win + . shortcut, now supports GIPHY. This change is related to the deprecation of the Google Tenor API.
Cumulative update KB5120240 installs automatically via Windows Update for Enterprise and Education editions. To check for the update manually, open Settings, go to the Windows Update section, and click Check for updates.
| Feature / Change | Performance Increase/Decrease | Optimization | PC Speed | Gaming Optimization |
|---|---|---|---|---|
| Secure Boot – new data for more accurate device targeting | 🟢 +2-5% Boot Time (fewer cert mismatches on startup) | 🟢 Medium – automatic certificate eligibility refinement | 🟢 Slight improvement (less authentication overhead during boot) | ⚪ No direct impact |
| Connectivity – updated COSA profile for SolNet-Mobile | ⚪ No measurable impact | 🟡 Low – carrier settings alignment | ⚪ No impact | ⚪ No impact |
| Device Management – MDM reliability after certificate expiry | 🟢 Prevents performance degradation on managed devices | 🟢 Medium – uninterrupted policy sync | 🟢 Prevents slowdown from failed MDM checks | ⚪ No impact |
| File History – enhanced SMB backup reliability | 🟢 +1-3% Network Copy Throughput (fewer retransmissions) | 🟢 Medium – scheduled task network access fixes | 🟡 Marginal (background task efficiency) | ⚪ No impact |
| Emoji Panel – GIPHY support replacing Google Tenor API | 🟡 Potential 50-100ms faster GIF loading (API latency change) | 🟡 Low – API backend swap | ⚪ No impact | ⚪ No impact |
Find and Change Settings
| Setting | Where to find | How to change |
|---|---|---|
| Secure Boot Certificate Updates | Settings > Windows Update > Advanced options > Optional updates | Secure Boot certificate updates are delivered automatically through Windows Update. To check for and install them, open Settings > Windows Update, click Advanced options, then select Optional updates. If available, the Secure Boot update will be listed and can be installed manually. On unmanaged devices, this rollout occurs gradually with no user action required. |
| Connectivity (COSA Profile for SolNet-Mobile) | Settings > Network & internet > Cellular > Mobile operator settings | COSA profile updates are applied automatically via Windows Update. To verify or manually refresh mobile operator settings, go to Settings > Network & internet > Cellular, select your SIM, and check under Mobile operator settings. If the updated profile is not yet applied, run Windows Update to receive the latest database. |
| MDM Certificate Expiry Behavior | Settings > Accounts > Access work or school | This reliability improvement is applied automatically through Windows Update. No manual configuration is required. After the update, managed devices will continue functioning normally even after the MDM certificate expires. To view your current MDM connection status, open Settings > Accounts > Access work or school and check the info for your enrolled account. |
| File History Backup (SMB Reliability) | Settings > System > Storage > Advanced storage settings > Backup options | This enhancement is applied automatically via Windows Update. To configure File History, open Settings > System > Storage > Advanced storage settings > Backup options, then select Add a drive or select a network location. After the update, scheduled File History tasks will access network folders over SMB more reliably. |
| Emoji Panel (GIPHY Support) | Emoji panel invoked by Win + . (period) | This change is applied automatically through Windows Update and no user action is required. After the update, pressing Win + . (period) opens the emoji panel, which now uses GIPHY instead of the deprecated Google Tenor API. No configuration is needed to enable or disable this change. |
Official announcement on the Microsoft website.
The last 10 Windows updates:
| Update | Build | Version | Windows | Channel | Date |
|---|---|---|---|---|---|
| KB5120996 | 28000.2796 | 26H1 | Windows 11 | Preview | 2026-08-14 |
| KB5120998 | 26200.9267 | 25H2 | Windows 11 | Preview | 2026-08-14 |
| KB5120240 | 22631.7517 | 23H2 | Windows 11 | Stable | 2026-08-11 |
| KB5120249 | 19045.7663 | 22H2 (ESU) | Windows 10 | Stable | 2026-08-11 |
| KB5121000 | 28000.2704 | 26H1 | Windows 11 | Stable | 2026-08-11 |
| KB5121003 | 26200.9168 | 25H2 | Windows 11 | Stable | 2026-08-11 |
| KB5101677 | 28020.2623 | 26H1 | Windows 11 | Beta | 2026-07-31 |
| KB5101680 | 28120.2630 | 26H1 | Windows 11 | Experimental | 2026-07-31 |
| KB5101683 | 26220.9022 | 25H2 | Windows 11 | Beta | 2026-07-31 |
| KB5101682 | 26300.9032 | 26H2 | Windows 11 | Experimental | 2026-07-31 |