CVE-2026-55018: CWE-416: Use After Free in Microsoft Microsoft 365 Apps for Enterprise
Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.
AI Analysis
Technical Summary
This vulnerability, identified as CVE-2026-55018 and classified under CWE-416 (Use After Free), affects Microsoft 365 Apps for Enterprise version 16.0.1. It allows an unauthorized attacker to execute code locally by exploiting a use-after-free condition in Microsoft Office. The CVSS v3.1 score is 7.8, indicating high severity with impact on confidentiality, integrity, and availability. Microsoft has released an official fix for this vulnerability and manages remediation for this cloud-hosted service. No known exploits have been reported in the wild.
Potential Impact
Successful exploitation could allow an attacker to execute arbitrary code locally, potentially leading to full compromise of the affected system's confidentiality, integrity, and availability. The vulnerability requires local access and user interaction to exploit.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the provided patch to Microsoft 365 Apps for Enterprise version 16.0.1 as soon as possible. Since this is a cloud service, Microsoft manages remediation server-side; verify the update status via the Microsoft Security Response Center advisory.
CVE-2026-55018: CWE-416: Use After Free in Microsoft Microsoft 365 Apps for Enterprise
Description
Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.
CVSS v3.1
Score 7.8high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability, identified as CVE-2026-55018 and classified under CWE-416 (Use After Free), affects Microsoft 365 Apps for Enterprise version 16.0.1. It allows an unauthorized attacker to execute code locally by exploiting a use-after-free condition in Microsoft Office. The CVSS v3.1 score is 7.8, indicating high severity with impact on confidentiality, integrity, and availability. Microsoft has released an official fix for this vulnerability and manages remediation for this cloud-hosted service. No known exploits have been reported in the wild.
Potential Impact
Successful exploitation could allow an attacker to execute arbitrary code locally, potentially leading to full compromise of the affected system's confidentiality, integrity, and availability. The vulnerability requires local access and user interaction to exploit.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the provided patch to Microsoft 365 Apps for Enterprise version 16.0.1 as soon as possible. Since this is a cloud service, Microsoft manages remediation server-side; verify the update status via the Microsoft Security Response Center advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-06-16T14:12:44.284Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Is Cloud Service
- true
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55018","vendor":"Microsoft"}]
Threat ID: 6a5676af68715ace43f09870
Added to database: 07/14/2026, 17:49:35 UTC
Last enriched: 08/13/2026, 15:29:20 UTC
Last updated: 08/26/2026, 22:52:11 UTC
Views: 33
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.