CVE-2026-55026: Microsoft Office Information Disclosure Vulnerability
This Microsoft advisory covers CVE-2026-55026 in Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019 and Microsoft SharePoint Server Subscription Edition.
- CVE-2026-55026
Key facts
- Vendor rating
- Medium, CVSS 6.2
- CISA KEV
- Not listed (catalogue checked )
- Affected
- Microsoft 365 Apps for Enterprise 16.0.1; Microsoft Office 2016 16.0.0; Microsoft Office 2019 19.0.0 and 8 more below
- Fixed in
- KB5002891 (build 16.0.5561.1001), KB5002892 (build 16.0.5561.1001), KB5002883 (build 16.0.10417.20175) and 3 more below
- Source published
- Source revised
- Listed by VulniPulse
Compiled by VulniPulse from the linked sources. How records are collected and checked.
Affected products & platforms
Description
Integer overflow or wraparound in Microsoft Office allows an unauthorized attacker to disclose information locally. Affected products named by the advisory: Microsoft SharePoint Enterprise Server 2016; Microsoft SharePoint Server 2019; Microsoft SharePoint Server Subscription Edition.
Text from the source record.
- Microsoft 365 Apps for Enterprise 16.0.1
- Microsoft Office 2016 16.0.0
- Microsoft Office 2019 19.0.0
- Microsoft Office 365 for Mac 1.0.0
- Microsoft Office LTSC 2021 16.0.1
- Microsoft Office LTSC 2024 16.0.0
- Microsoft Office LTSC for Mac 2021 16.0.1
- Microsoft Office LTSC for Mac 2024 16.0.0
- Microsoft SharePoint Enterprise Server 2016 16.0.0
- Microsoft SharePoint Server 2019 16.0.0
- Microsoft SharePoint Server Subscription Edition 16.0.0
Official advisory · high-confidence parse· fetched ·verify at source
How to fix CVE-2026-55026
Upgrade to a fixed release named by Microsoft:
- KB5002891 (build 16.0.5561.1001)
- KB5002892 (build 16.0.5561.1001)
- KB5002883 (build 16.0.10417.20175)
- KB5002885 (build 16.0.10417.20175)
- KB5002882 (build 16.0.19725.20434)
- KB5002887 (build 16.0.5561.1000)
Vendor guidance
- Install the applicable security update for your platform: KB5002891, KB5002892, KB5002883, KB5002885, KB5002882, KB5002887 (see the Microsoft Update Catalog).
End-of-life dates for Microsoft SharePoint Server
More Microsoft Server advisories
CVE-2026-97783Oct 13, 2026Microsoft Office SharePoint Spoofing VulnerabilityCVE-2026-69943Oct 13, 2026Microsoft Office SharePoint Remote Code Execution VulnerabilityCVE-2026-120000Nov 10, 2026Microsoft Office SharePoint Remote Code Execution VulnerabilityCVE-2026-124210Nov 10, 2026Microsoft Office SharePoint Information Disclosure VulnerabilityCVE-2026-123391Nov 10, 2026Microsoft Office SharePoint Elevation of Privilege VulnerabilityCVE-2026-123390Nov 10, 2026Microsoft Office SharePoint Remote Code Execution Vulnerability
Microsoft Server advisories, July 2026All Microsoft Server advisories
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