Microsoft released KB5064010 on August 12, 2025 — a hotpatch targeted at Windows 11 Enterprise LTSC 2024 (OS Build 26100.4851) that delivers a focused set of security fixes designed to take effect without the usual reboot required by standard cumulative updates.
Microsoft’s hotpatch technology is a shift in the Windows servicing model: instead of delivering large cumulative updates that replace on-disk binaries and require a reboot, hotpatches apply narrowly scoped security fixes to running code so protection is immediate and user disruption is minimized. The hotpatch cadence complements quarterly baseline (cumulative) months with lighter, reboot-free updates in the intervening months, reducing the number of forced restarts for eligible enterprise devices from twelve a year to four. This operating model is now available to eligible Windows 11 Enterprise installations, and KB5064010 is the August 12, 2025 hotpatch entry for LTSC 2024 clients.
If any claim in an external write-up or community thread cannot be corroborated by Microsoft documentation or vendor advisories (for example, community reports of specific hardware breakages tied to unrelated baseline updates), treat those reports as anecdotal until validated by vendor guidance or reproducible telemetry from your own pilot.
Hotpatches are a powerful new tool in the enterprise update toolbox — one that improves security posture without forcing immediate downtime — but they are not a panacea. When used in combination with standard quarterly baselines, disciplined testing, and updated operational tooling, they can meaningfully reduce risk and improve uptime for LTSC environments. (support.microsoft.com, techcommunity.microsoft.com, bleepingcomputer.com)
Source: Microsoft Support August 12, 2025—KB5064010: Hotpatch for Windows 11 Enterprise LTSC 2024 (OS Build 26100.4851) - Microsoft Support
Microsoft’s hotpatch technology is a shift in the Windows servicing model: instead of delivering large cumulative updates that replace on-disk binaries and require a reboot, hotpatches apply narrowly scoped security fixes to running code so protection is immediate and user disruption is minimized. The hotpatch cadence complements quarterly baseline (cumulative) months with lighter, reboot-free updates in the intervening months, reducing the number of forced restarts for eligible enterprise devices from twelve a year to four. This operating model is now available to eligible Windows 11 Enterprise installations, and KB5064010 is the August 12, 2025 hotpatch entry for LTSC 2024 clients. Why this matters now
Enterprises running the Long-Term Servicing Channel rely on LTSC builds for stability and minimal feature churn. Security remains non-negotiable, however, and hotpatches give administrators an option to remediate vulnerabilities rapidly while keeping mission-critical endpoints running uninterrupted. The August 12 hotpatch specifically targets Windows 11 Enterprise LTSC 2024 and registers as OS Build 26100.4851, making it the canonical fixpack for environments on that LTSC baseline that meet the hotpatch prerequisites.What KB5064010 actually is (clear summary)
- KB number: KB5064010 (hotpatch release).
- Target platform: Windows 11 Enterprise LTSC 2024 (version 24H2 lineage).
- OS build after install: 26100.4851 (identifies the hotpatched build).
- Purpose: deliver security fixes (no feature additions) that apply immediately and do not require a restart on eligible devices for the remainder of the quarter.
Eligibility and prerequisites (what an admin must verify)
Before expecting KB5064010 to appear as a hotpatch option, environments must meet Microsoft's documented prerequisites:- Licensing: eligible subscriptions such as Windows 11 Enterprise E3/E5, Microsoft 365 Business Premium, Windows 365 Enterprise, or equivalent education/enterprise SKUs.
- OS and baseline: devices must be running Windows 11 Enterprise, version 24H2 (LTSC 2024 fits this), on a current baseline (Build 26100.2033 or later historically required for initial hotpatch availability). Verify your baseline and current build before proceeding.
- Management: Microsoft Intune and a hotpatch-enabled Windows quality update policy (Windows Autopatch integration simplifies opt-in). Hotpatch distribution relies on Intune/Autopatch for policy-driven rollouts.
- Virtualization-based Security (VBS): VBS must be enabled where required by Microsoft’s guidance for hotpatch eligibility.
How hotpatching behaves in practice
Immediate-on-installation protection
Hotpatches are designed to take effect immediately upon installation by patching in-memory code paths or otherwise ensuring that the fix is active in the running system. This is different from standard cumulative updates that typically require a restart to replace on-disk components and get the new code into memory. The hotpatch model therefore shrinks the window between patch publication and protection. (techcommunity.microsoft.com, bleepingcomputer.com)What hotpatches do not do
- They are not a substitute for cumulative baseline updates. Hotpatches deliver security-only fixes. Feature or reliability rollups continue to be delivered in baseline months and still require the usual restart.
- They may have narrower coverage for changes that fundamentally require on-disk binary replacement or firmware updates; these scenarios still force a restart.
Visibility and tracking
On devices eligible for hotpatching, updates appear under different KB numbers and OS build metadata than devices receiving the standard restart-required cumulative update. Administrators should track both the KB number and OS build for reporting and compliance audits. KB5064010 maps to build 26100.4851 for this particular release.Deployment guidance — practical, step-by-step
The following walk-through outlines a conservative approach to roll out KB5064010 in an enterprise LTSC environment:- Inventory and baseline verification
- Confirm each target device is Windows 11 Enterprise LTSC 2024 (winver or SCCM/Intune inventory).
- Confirm devices are on a baseline that Microsoft requires for hotpatch eligibility (historically Build 26100.2033 or later). If they are not, schedule a baseline cumulative update during a maintenance window.
- Licensing and management check
- Ensure organization has the required subscription SKU and that devices are enrolled in Intune (or Windows Autopatch where used).
- Prepare Arm64 devices (if any)
- Evaluate the CHPE disablement impact on x86 emulation workloads. If acceptable, implement CHPE disable via the DisableCHPE CSP or set the HotPatchRestrictions registry key and reboot once to apply. Document this change.
- Test in a limited pilot group
- Create a pilot device group in Intune and enable hotpatch delivery via a Windows quality update policy (set “When available, apply without restarting the device” to Allow where applicable). Deploy KB5064010 to pilot devices first. Monitor for application compatibility, driver issues, and functional regressions.
- Expand rollout in rings
- Gradually broaden the policy from pilot → early adopter → broad deployment, with monitoring and rollback plans at each stage. Use Intune reporting and event logs to validate installation and patch effectiveness.
- Post-deployment verification and compliance reporting
- Record OS Build values (26100.4851 for KB5064010) across assets to confirm successful hotpatch application. Ensure SOC monitoring/EDR products are updated to reflect the new patched state.
Testing and rollback considerations
- Application compatibility testing remains essential. Hotpatches alter running code paths and, in rare cases, can interact with kernel-mode drivers or third-party security products in unexpected ways. Pilot test across representative hardware and software stacks.
- If a hotpatch produces an adverse effect, the typical remediation is to uninstall the hotpatch from the affected device (where possible), apply mitigations, or fall back to the baseline cumulative update cycle if necessary. Documented uninstallability varies by update and organization management policies; test uninstall in the pilot.
- Because hotpatches keep the system online, some classes of failures may be subtler than with reboot-driven updates — invest in robust logging and telemetry to detect regressions fast.
Security and operational advantages
- Reduced attack window: fixes are applied immediately and take effect without waiting for a restart, reducing exposure time between patch publication and protection.
- Improved uptime: mission-critical endpoints and users suffer fewer disruptions, improving productivity and reducing helpdesk tickets for restart-related problems.
- Smaller update payloads: hotpatches are scoped to security changes rather than full cumulative rollups, reducing network impact for large-scale deployments.
Risks, limitations, and the unknowns
No update model is risk-free. Hotpatching presents distinct trade-offs that administrators must consider and mitigate.Compatibility and third-party drivers
Hotpatches modify code paths in-memory; third-party kernel drivers and security/EDR agents that hook into OS internals are a known point of friction historically. Organizations must validate critical vendors’ compatibility statements and include their products in pilot testing. Incidents from previous baseline rollouts have shown that driver or firmware mismatches can lead to serious issues such as boot or stability problems — anecdotal community reports of boot loops after earlier 24H2 cumulative updates underline the need for careful testing. These are community reports and should be used to inform testing priorities rather than as proof of systemic failure. (reddit.com, bleepingcomputer.com)Edge-case behavior and incompleteness
Hotpatches intentionally remain narrow. For vulnerabilities tied to components that require on-disk replacement, hotpatching is not possible; the full cumulative baseline remains the authoritative remedy. Administrators must not treat hotpatches as a complete replacement for scheduled maintenance cycles.Visibility and auditability
Because hotpatches change the way patch state is represented (different KB numbers, different reported build values), asset management and compliance tooling must be updated to recognize hotpatched state. Otherwise, audits could mistakenly flag patched devices as unpatched. Confirm that SCCM, Intune reporting, CMDB, and SIEM integrations correctly reflect hotpatched builds and KB identifiers. (support.microsoft.com, techcommunity.microsoft.com)Arm64 caveats
Disabling CHPE on Arm64 devices is a one-time prerequisite for hotpatch eligibility but may have performance or compatibility implications for x86 emulation workloads. Confirm vendor support and test critical workloads thoroughly before making the change broadly.Monitoring and verification checklist (quick reference)
- Verify device is running Windows 11 Enterprise LTSC 2024 and on an eligible baseline.
- Confirm enrollment in Intune and correct assignment to a hotpatch-enabled Windows quality update policy.
- Validate subscription/license eligibility for hotpatch features.
- For Arm64: ensure CHPE disablement is applied and documented.
- After deployment: confirm OS Build shows 26100.4851 for devices that received KB5064010.
Best-practice recommendations
- Maintain quarterly baseline cycles even if you adopt hotpatching; hotpatches are not a replacement for cumulative maintenance.
- Start with a narrow pilot that mirrors production diversity (hardware vendors, disk encryption, EDR agents, virtualization platforms).
- Keep firmware and driver inventories up to date; hotpatches won’t protect against vulnerabilities tied to firmware or device microcode. Schedule firmware updates in controlled maintenance windows.
- Update operational runbooks and compliance dashboards to capture hotpatch KB identifiers and new build numbers. This prevents false negatives in vulnerability and compliance scans.
Verification and cross-references
Key technical claims in this article — the hotpatch release date, KB number, hotpatch behavior (no restart), the build number (26100.4851), Intune/Autopatch management path, Arm64 CHPE requirement, and licensing prerequisites — were verified against Microsoft’s official KB article for KB5064010 and Microsoft’s Windows IT Pro communications describing the hotpatch program. Independent reportage from security press confirms the practical behavior of hotpatches and provides additional operational color on adoption and rollout considerations. Administrators should treat vendor bulletins and Microsoft’s published guidance as the authoritative source when implementing changes. (support.microsoft.com, techcommunity.microsoft.com, bleepingcomputer.com)If any claim in an external write-up or community thread cannot be corroborated by Microsoft documentation or vendor advisories (for example, community reports of specific hardware breakages tied to unrelated baseline updates), treat those reports as anecdotal until validated by vendor guidance or reproducible telemetry from your own pilot.
Conclusion
KB5064010 — the August 12, 2025 hotpatch for Windows 11 Enterprise LTSC 2024 (OS Build 26100.4851) — is emblematic of Microsoft’s effort to balance security with operational continuity for enterprise customers. For organizations that meet the documented prerequisites, hotpatching can materially reduce user disruption while closing critical security gaps more quickly than traditional restart-required patches. That said, hotpatch adoption must be approached methodically: validate licensing and management posture, pilot thoroughly across representative workloads (including third-party security and kernel-mode drivers), and maintain disciplined baseline cycles and firmware update plans.Hotpatches are a powerful new tool in the enterprise update toolbox — one that improves security posture without forcing immediate downtime — but they are not a panacea. When used in combination with standard quarterly baselines, disciplined testing, and updated operational tooling, they can meaningfully reduce risk and improve uptime for LTSC environments. (support.microsoft.com, techcommunity.microsoft.com, bleepingcomputer.com)
Source: Microsoft Support August 12, 2025—KB5064010: Hotpatch for Windows 11 Enterprise LTSC 2024 (OS Build 26100.4851) - Microsoft Support