Use after free in Windows DWM Core Library allows an authorized attacker to elevate privileges locally.
In plain language
Written by AI from the record
CVE-2026-62888 is a Windows flaw that can let a local attacker gain higher privileges on affected versions; small businesses should act by updating Windows to the listed fixed releases.
CVE-2026-62888 is a Windows DWM Core Library elevation-of-privilege issue caused by a use-after-free condition (CWE-416) that can be triggered by an authorized local attacker to elevate privileges on Windows 10, Windows 11, and Windows Server 2022/2025.
If you're affected
Full admin-level takeover
Malware running with higher rights
Service disruption
Data access after escalation
What is it
This is a Windows bug in the graphics/windowing part of the system. If someone can already run code on your computer (“local” access), the bug can be used to get much higher privileges—similar to turning an ordinary account into an administrator account.
Who is affected
This matters if you run Windows 10, Windows 11, Windows Server 2022, or Windows Server 2025 on devices that could be accessed by someone who can run code locally (for example, after an account compromise or local access).
Because this is a local elevation-of-privilege weakness, it’s primarily a risk when an attacker already has the ability to execute something on the machine; it is not described here as broadly reachable over the internet by itself.
How urgent is it
Mark this as urgent (RED) because the bug enables local privilege escalation in a core Windows component, which can turn an initial foothold into full control. The vulnerability is tied to a new patch cycle and is associated with threat-actor activity reported in the latest coverage.
What to do — in detail
Confirm exposure (what to check)
On each affected device/server, open System Information (or use your standard inventory tool) and capture:
Windows edition (Windows 10 / Windows 11 / Windows Server 2022 / Windows Server 2025)
OS build number (and ideally the full version like “10.0.xxxxx.y”)
Determine whether the device matches any of the affected builds before the fix by checking whether it is already on a fixed build listed below. If you are not on the fixed build, treat it as needing the security update for CVE-2026-62888.
Apply the fixed version (target versions)
Update to a Microsoft release that matches one of these fixed versions (pick the one for your OS/branch):
Windows 10: 10.0.19044.7663 and 10.0.19045.7663
Windows 11: 10.0.22631.7517, 10.0.26100.9106, 10.0.26200.9106, 10.0.28000.2704, 10.0.26100.9168, 10.0.26200.9168
Windows Server 2022: 10.0.20348.5440 and 10.0.20348.5499
Windows Server 2025: 10.0.26100.33222 and 10.0.26100.33296
Vendor guidance (use the Microsoft update page for the exact package(s) for your environment):
Follow your normal patch-management practice (pilot one machine/one server role first if you have strict uptime needs), but prioritize this update because it is a privilege escalation issue.
Ensure reboot/maintenance windows are planned as required by your patch process; some Windows updates require restart to fully apply.
Temporary workaround (if patching is delayed)
Restrict who can log on locally and reduce the chance of local code execution (for example, enforce least privilege, tighten local admin usage, and ensure endpoint access is well-controlled). While this doesn’t remove the underlying bug, it reduces the “local authorized attacker” condition described for this type of issue.
What to monitor after patching
Confirm the device OS build number matches the fixed versions above.
Watch for unusual privilege changes or suspicious local admin activity patterns on endpoints/servers during the patch window (use your existing security monitoring tools).
Technical context
What’s happening
Vulnerability class: CWE-416 (Use After Free).
Mechanism: a use-after-free in the Windows DWM Core Library can allow an authorized local attacker to elevate privileges.
Exposure and exploitation status
The findings provided do not list this in CISA KEV and report no public exploit code on record.
Despite that, the traffic-light verdict for this CVE is RED, and the findings note patch-related attention (including actor association in reporting), which supports treating this as high priority.
Impact summary
Because the bug can enable privilege escalation locally, successful exploitation can lead to admin-level control, which in turn can be used to access sensitive data and disrupt operations.
Patch information
Fixed build numbers are explicitly listed in the findings via Microsoft’s update guidance page for CVE-2026-62888. Follow those build targets for each Windows edition/branch.
This is a general assessment based on public vulnerability data. It does not account for your specific infrastructure — when in doubt, consult a security specialist.
