CVE-2026-55026 — Microsoft Office Information Disclosure Vulnerability

Executive Summary

Integer overflow or wraparound in Microsoft Office allows an unauthorized attacker to disclose information locally.

Overview

6.2

CVSS MEDIUM

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Information Disclosure

Released Jul 14 2026

Last Updated Jul 14 2026

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

CVSS Vector

ATTACK VECTOR

Local

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

None

AVAILABILITY

None

EXPLOIT CODE MATURITY

Unproven

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 5.4

EPSS Score

No EPSS score available for this CVE.

View on FIRST.org

Affected Products

14 affected products

Product	KB Article	Severity	Impact	Restart Required
Microsoft 365 Apps for Enterprise for 32-bit Systems	`Click to Run (Security Update)`	Important	Information Disclosure	No
Microsoft 365 Apps for Enterprise for 64-bit Systems	`Click to Run (Security Update)`	Important	Information Disclosure	No
Microsoft Office 2016 (32-bit edition)	`5002887 (Security Update)`	Important	Information Disclosure	Maybe
Microsoft Office 2016 (64-bit edition)	`5002887 (Security Update)`	Important	Information Disclosure	Maybe
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
Microsoft Office 365 for Mac	`Release Notes (Security Update)`	Important	Information Disclosure	Maybe
Microsoft Office LTSC 2021 for 32-bit editions	`Click to Run (Security Update)`	Important	Information Disclosure	No
Microsoft Office LTSC 2021 for 64-bit editions	`Click to Run (Security Update)`	Important	Information Disclosure	No
Microsoft Office LTSC 2024 for 32-bit editions	`Click to Run (Security Update)`	Important	Information Disclosure	No
Microsoft Office LTSC 2024 for 64-bit editions	`Click to Run (Security Update)`	Important	Information Disclosure	No
Microsoft Office LTSC for Mac 2021	`Release Notes (Security Update)`	Important	Information Disclosure	Maybe
Microsoft Office LTSC for Mac 2024	`Release Notes (Security Update)`	Important	Information Disclosure	Maybe
Microsoft SharePoint Enterprise Server 2016 5002891 (Security Update) 5002892 (Security Update) Important Information Disclosure 5002880 5002881 Base: 6.2 Temporal: 5.4 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C 16.0.5561.1001 Maybe None Microsoft SharePoint Server 2019 5002883 (Security Update) 5002885 (Security Update) Important Information Disclosure 5002874 5002876 Base: 6.2 Temporal: 5.4 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C 16.0.10417.20175 Maybe None Microsoft SharePoint Server Subscription Edition	`5002882 (Security Update)`	Important	Information Disclosure	Maybe

Patches

4 patches

Article	Type	Restart
`Click to Run`	Security Update	No
`5002887`	Security Update	Maybe
`Release Notes`	Security Update	Maybe
`5002882`	Security Update	Maybe

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

Haein Lee

References

MSRC Advisory MITRE NVD