Microsoft Office
CVE-2018-8558 — Microsoft Outlook Information Disclosure Vulnerability
Executive Summary
An information disclosure vulnerability exists when Microsoft Outlook fails to respect "Default link type" settings configured via the SharePoint Online Admin Center. A malicious user could potentially share anonymously-accessible links to other users via email where these links are intended to be accessed only by specific users. The security update addresses the vulnerability by correcting how Microsoft Outlook generates links inserted into emails via the "Attach File" interface.
Overview
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
EPSS Score
0.05585
probability of exploitation in the next 30 days
0.92188 percentile - updated 2026-08-14
View on FIRST.org
Affected Products
4 affected products
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Microsoft Office 2019 for 32-bit editions | Click to Run (Security Update) |
Important | Information Disclosure | No |
| Microsoft Office 2019 for 64-bit editions | Click to Run (Security Update) |
Important | Information Disclosure | No |
| Office 365 ProPlus for 32-bit Systems | Click to Run (Security Update) |
Important | Information Disclosure | No |
| Office 365 ProPlus for 64-bit Systems | Click to Run (Security Update) |
Important | Information Disclosure | No |
Patches
1 patch
| Article | Type | Restart |
|---|---|---|
Click to Run |
Security Update | No |
Known Exploits
No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.
Acknowledgments
None
References
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