CVE-2026-62798

This vulnerability is a problem in Windows that could let someone with a low-level account who can log into your computer read confidential information sitting in system memory. Think of it like a “memory book” that shouldn’t be readable—but due to a checking mistake, the wrong person can peek inside. There’s no need for the user to click anything; it’s triggered by local access.

This matters if you run Windows 11 or Windows Server 2025 and you have machines where low-privilege users can get local access (for example, employees, contractors, or anyone with a standard account who can log on). It only becomes a meaningful risk when an attacker can already access the machine and act as a local, low-privilege user; it does not require user interaction.

This is RED because the flaw is reachable on default Windows configurations and allows a local, low-privilege attacker to read sensitive information from memory without any user interaction. While no clear dated exploitation report or public exploit is listed here, patching should be prioritized because it closes an information-disclosure path that can be used after someone gets local access.

1. Confirm exposure on each device

   • Identify all endpoints and servers running Windows 11 and Windows Server 2025.
   • For each device, record the exact Windows build number.
   • Determine whether the device has untrusted or low-privilege users who can log in locally (since the attack requires local low-privilege access).

2. Check against Microsoft fixed builds

   • Windows 11 is fixed in any of these builds: 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 2025 is fixed in any of these builds: 10.0.26100.33222, 10.0.26100.33296.
   • If your device build is older than the fixed build for its branch/line, plan to upgrade to the fixed version.

3. Upgrade / remediate

   • Apply the Microsoft updates that include the fixed versions listed above.
   • Re-check the OS build after reboot to confirm the device is now on a fixed build.

4. Temporary workaround if patching is delayed

   • Limit who can log on locally to affected Windows machines.
   • Remove unnecessary local permissions and ensure non-admin users do not have local administrative access.

5. What to monitor after changes

   • Review any relevant access activity on affected machines (especially logons by standard users on systems you consider higher-value).
   • Watch for unusual repeated local access attempts by non-admin accounts (the vulnerability is local, so local account activity matters).

CVE-2026-62798 is a Windows Win32K information disclosure vulnerability (CWE-822, untrusted pointer dereference). The mechanism described in the findings is that Win32K fails to properly validate pointers, allowing a local attacker with low privileges to access and view confidential information from system memory. Conditions: the attacker must have local access; no user interaction is required; default configuration reachability is reported as true for the affected products (Windows 11 and Windows Server 2025).

Exploitation status in the provided findings: not listed in CISA KEV; no clear dated press claim of exploitation; no public exploit code on record. Patch availability is confirmed with multiple fixed Windows build numbers for both Windows 11 and Windows Server 2025. The provided traffic-light verdict is RED, indicating immediate remediation priority despite limited public exploitation evidence in the findings. Technical details beyond pointer validation are not expanded in the provided material.