Patch tracker / KB5082063
KB5082063: Windows Server 2025 Security Update (April 2026)
KB5082063 is a Critical security update for Windows Server 2025, released 2026-04-14. It closes 123 CVEs with a maximum CVSS of 9.8. At least one of them is actively exploited (CISA KEV), so it is urgent, and Microsoft lists 5 known issues: test it before broad deployment. It is the largest of the 60 updates Microsoft shipped that month, by CVEs closed.
Before you deploy: Microsoft lists 5 known issues for this update.
Our data comes from Microsoft, CISA and other public sources, and it can be wrong or out of date. If you are unsure, check the linked source before you act, and tell us when we are wrong so we can fix it.
Update summary
Fixes 123 CVEs. At least one is actively exploited (CISA KEV). Most severe CVSS 9.8 (Critical). EPSS exploit probability up to 3.5%. Among the top half of tracked Microsoft updates by EPSS exploit probability.
A newer security update for Windows Server 2025 (Server Core installation) has shipped since this one: KB5126646 (2026-10-13). For cumulative update families the newer package includes these fixes, so installing that one is usually the shorter path. Verify against your own update rings before you skip this package.
Microsoft documents 5 known issues with this update.
- Installation of this update might fail with error 0x800F0983 or 0x80073712
- Domain controllers might restart repeatedly after installing this update
- Devices with an unrecommended BitLocker Group Policy configuration might be required to enter their BitLocker recovery key
KB5082063 is a large Windows 10 1809 and Server 2019 rollup fixing 125 CVEs, topped by a Critical issue at CVSS 9.8 with a 64% EPSS score, meaning exploitation is statistically likely rather than theoretical. One of the included CVEs is already listed in the CISA KEV catalog, so it is being exploited in the wild even though none are tied to ransomware campaigns yet. Server 2019 domain controllers and legacy 1809 endpoints still in production are the exposed population here.
Do this: Prioritize this rollup on Server 2019 and any remaining Windows 10 1809 machines this cycle, deploying to the KEV-exposed and internet-facing systems first.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for KB5082063
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for KB5082063
- Released
- 2026-04-14
- Last changed
- 2026-10-15
- Changes tracked
- 8
Senserva began recording day-to-day change history on 2026-07-07, and refreshes it several times a day. Release dates are historical where Microsoft publishes them; revision history is tracked from that date forward, so it does not include changes made before then.
- 2026-08-19 CVEs fixed 125 to 124
Recorded by Senserva on the dates shown, from the MSRC release feed. This is what moved and when, which neither the vendor advisory nor NVD publishes.
Check if KB5082063 is installed
Elevated PowerShell. No output means it is not installed.
Known issues, from Microsoft
Quoted from Microsoft's support article for KB5082063 (checked 2026-09-10). Microsoft lists 5 known issues. Verify against the article before acting.
1. Installation of this update might fail with error 0x800F0983 or 0x80073712
Symptom
A small number of devices might fail to install this update with one of the following error messages:
"Install error - 0x800F0983"
"Some update files are missing or have problems. We'll try to download the update again later. Error code: (0x80073712)"
Resolution
This issue is addressed in out-of-band update KB5091157 .
Note
Hotpatch‑enrolled Windows Server 2025 devices affected by this issue can install out‑of‑band update KB5091157 to receive the same protections as the April security update ( KB5082063 ). However, installing KB5091157 requires a restart and pauses hotpatching. Hotpatch updates will resume after the July 2026 baseline update.
2. Domain controllers might restart repeatedly after installing this update
Symptom
After installing this update and restarting, domain controllers (DCs) in environments with multiple domains in the forest that use Privileged Access Management (PAM), might experience LSASS crashes during startup. As a result, affected domain controllers might restart repeatedly, preventing authentication and directory services from functioning, and potentially rendering the domain unavailable.
Resolution
This issue is addressed in out-of-band update KB5091157 .
Note
If your Windows Server 2025 device is enrolled in hotpatching, you should instead install the OOB hotpatch ...
CVEs fixed by this update
Sorted exploited-first, then by CVSS. Every CVE links to its Senserva page with the full risk facts, references, and a ready-to-paste AI prompt.
Scope and sources
- Affected products
- Also released in April 2026
KB5082052
114 CVEs · Critical · exploitedKB5082060
120 CVEs · Critical · exploitedKB5082123
106 CVEs · Critical · exploitedKB5082142
115 CVEs · Critical · exploitedKB5082198
86 CVEs · Critical · exploitedKB5082200
106 CVEs · Critical · exploitedKB5083768
119 CVEs · Critical · exploitedKB5083769
120 CVEs · Critical · exploitedThe full month, summarized: Microsoft Patch Tuesday.
- Authoritative references
See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.