Critical Vulnerability CVE-2026-7345 Affects Multiple Microsoft Products

Microsoft has released security guidance for a critical vulnerability affecting multiple products. Attackers can exploit this vulnerability to execute arbitrary code with system privileges. Organizations must apply updates immediately.

Affected Products

The vulnerability impacts the following Microsoft products:

• Windows 10 (version 1903 and later)
• Windows 11 (all versions)
• Windows Server 2019 and 2022
• Microsoft Office 2019 and 2021
• Microsoft 365 Apps for Enterprise

Severity Information

• CVE ID: CVE-2026-7345
• CVSS Score: 9.8 (Critical)
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Changed
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

Technical Details

The vulnerability exists in the way Microsoft Windows handles objects in memory. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker could take control of the affected system.

Attackers could then install programs, view, change, or delete data, or create new accounts with full user rights. The vulnerability could also allow an attacker to run arbitrary code in the context of the local system account.

Mitigation Steps

Microsoft has released security updates to address this vulnerability. Organizations should apply these updates as soon as possible.

Apply Security Updates

1. For Windows systems:

   • Go to Windows Update and install all available updates
   • For Windows Server systems, use Windows Server Update Services (WSUS)

2. For Microsoft Office and Microsoft 365:

   • Open any Office application
   • Go to File > Account > Update Options > Update Now

Workarounds

If unable to apply updates immediately, Microsoft recommends the following workarounds:

1. Enable Windows Defender Exploit Guard:

   • Open Windows Security
   • Go to App & browser control
   • Under Exploit protection settings, configure to use system settings

2. Block TCP port 445 at the firewall:

   • This may impact legitimate applications that use this port

3. Enable Enhanced Mitigation Experience Toolkit (EMET):

   • Download from Microsoft EMET

Timeline

• Discovery: June 15, 2026
• Public Disclosure: July 1, 2026
• Patch Release: July 12, 2026
• Exploitation Detected: July 13, 2026

Microsoft has not detected any widespread exploitation of this vulnerability at this time. However, the vulnerability is being actively exploited in limited targeted attacks.

Additional Resources

• Microsoft Security Advisory
• Microsoft Security Response Center
• Windows Update
• Microsoft Security Blog

Organizations should monitor their systems for unusual activity and ensure all Microsoft products are up to date. Additional information will be provided as it becomes available.