Microsoft Windows Management Console (MMC) Security Feature Bypass CVE-2025-26633

Historical catalog analysis: CISA added this entry on March 11, 2025. The entry reflects catalog information retrieved on August 31, 2026, not a snapshot archived on the inclusion date. Check current vendor guidance before acting.

What the vulnerability is

CVE-2025-26633 is an improper neutralization vulnerability (CWE-707) affecting the Microsoft Windows Management Console (MMC). This flaw allows an unauthorized attacker to bypass a security feature locally. The vulnerability has been identified as being used in known ransomware campaigns.

Exposure and applicability

This vulnerability applies to environments utilizing the Microsoft Windows Management Console. Because the exploit occurs locally, exposure is primarily relevant to systems where an attacker has already gained initial access or where local privilege escalation paths are being sought. Infrastructure owners should prioritize assets that serve as administrative jump boxes or high-value targets where MMC is frequently deployed for system management.

Remediation priorities

Based on the reported exploitation by ransomware actors, our analysis suggests the following prioritization:

1. Vendor Mitigation Deployment: The primary corrective action is to apply mitigations according to Microsoft’s instructions. This should be prioritized for all Windows endpoints and servers where MMC is active.
2. Cloud Service Alignment: For organizations utilizing cloud-based Windows deployments, remediation should align with BOD 22-01 guidance to ensure consistent exposure reduction across hybrid environments.
3. Product Decommissioning: In scenarios where vendor mitigations cannot be applied or are unavailable for a specific legacy version, the product should be discontinued to eliminate the attack surface.

How to validate remediation

Verification must move beyond simple version checks, as a deployed patch does not inherently prove that the security feature bypass is no longer possible in a specific configuration. Defenders should:

• Confirm Mitigation Application: Verify through configuration management tools that the vendor-supplied mitigations are active across all targeted assets.
• Validate Security Feature Integrity: Use authorized security validation tools to confirm that the specific security feature previously bypassed by CVE-2025-26633 is now functioning as intended.
• Audit Local Access: Review local account permissions and access logs to ensure that the prerequisites for a local bypass are minimized, reducing the likelihood of successful exploitation even if a patch fails.

Limits and open questions

While vendor mitigations reduce exposure, residual risk remains if attackers utilize alternative local bypass methods not addressed by this specific fix. The source indicates the vulnerability allows for a local bypass; however, it does not detail the specific security feature being bypassed or the exact mechanism of neutralization failure. Consequently, defenders must assume that other local vulnerabilities may exist within the MMC framework.

Source and editorial note

CVE-2025-26633: Microsoft Windows Management Console (MMC) Improper Neutralization Vulnerability · Source date: March 11, 2025 · Retrieved August 31, 2026.

Material facts are tied to the cited primary source. Recommendations are independent defensive analysis unless attributed to the source. Confirm consequential decisions against current authoritative guidance.

Archive date: March 14, 2025. The displayed post date is assigned three days after the source date to organize this retrospective archive; it does not mean this site published the analysis then. First published by this site: October 22, 2026 at 00:06 UTC.

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