Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:L) | Local access needed |
| Attack complexity (AC:H) | High complexity |
| Privileges required (PR:L) | Low privileges required |
| User interaction (UI:N) | No user interaction |
| Scope (S:U) | Scope unchanged |
| Confidentiality (C:H) | High confidentiality impact |
| Integrity (I:H) | High integrity impact |
| Availability (A:H) | High availability impact |
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
About Microsoft Windows 11 24h2
CVE-2026-56187 affects Microsoft Windows 11 24h2, a product from Microsoft. Before acting, confirm where Microsoft Windows 11 24h2 runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: Use after free in Windows MIDI Service Module allows an authorized attacker to elevate privileges locally.
The weakness class is Use After Free. Memory is used after it was released, which can lead to code execution.
Based on its CVSS vector, the flaw needs local or adjacent access, needs some level of access, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Microsoft Windows 11 24h2 |
| Affected versions | Windows 11 24h2 before 10.0.26100.8875; Windows 11 25h2 before 10.0.26200.8875; Windows 11 26h1 before 10.0.28000.2525 |
| Published | Jul 14, 2026 |
| Last modified | Jul 23, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | secure@microsoft.com |
How to detect it
- Inventory every instance of Microsoft Windows 11 24h2 and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Microsoft Windows 11 24h2 named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Microsoft Windows 11 24h2 to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-416: Use After Free More CVEs with this weakness
Technical References
Frequently asked questions
Related CVEs
Use after free in Microsoft Edge (Chromium-based) allows an unauthorized attacker to elevate privileges locally.
Insufficient verification of data authenticity in Azure Billing allows an unauthorized attacker to elevate privileges over a network.
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Improper neutralization of special elements used in a command ('command injection') in M365 Copilot allows an authorized attacker to elevate privileges over a network.
Improper access control in Azure Logic Apps allows an unauthorized attacker to elevate privileges over a network.
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