EUVD-2026-44205
GHSA-p4qf-r8q8-f438
Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Local file-based trigger requires victim interaction, no attacker privileges needed; impact is confidentiality-only with no integrity or availability consequence.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
2DescriptionCVE.org
Integer overflow or wraparound in Microsoft Office allows an unauthorized attacker to disclose information locally.
AnalysisAI
Microsoft Office information disclosure via integer overflow (CWE-190) exposes high-confidentiality data to a local attacker who can induce a victim to open a crafted document. The flaw affects a broad range of Microsoft Office versions on both Windows and macOS - including Office 2016, 2019, LTSC 2021, LTSC 2024, and Microsoft 365 Apps for Enterprise - confirmed by Microsoft via MSRC. No public exploit code exists and CISA SSVC rates exploitation as none, placing this in low urgency despite the High confidentiality impact in the CVSS vector; however, the extensive product footprint means patching remains advisable.
Technical ContextAI
CWE-190 (Integer Overflow or Wraparound) occurs when an arithmetic operation produces a value that exceeds the maximum size of the integer type, causing the result to wrap around to an unintended value. In the context of Microsoft Office file parsing or document processing, such an overflow can corrupt size or offset calculations that govern memory reads, potentially causing the application to read and expose memory contents that should be inaccessible. The vulnerability is present across the Microsoft Office ecosystem on both Windows and macOS platforms, as confirmed by CPE strings covering cpe:2.3:a:microsoft:microsoft_365_apps_for_enterprise, microsoft_office_2016, microsoft_office_2019, microsoft_office_ltsc_2021, microsoft_office_ltsc_2024, microsoft_office_365_for_mac, microsoft_office_ltsc_for_mac_2021, and microsoft_office_ltsc_for_mac_2024. The root cause is a failure to validate or bound-check integer arithmetic prior to using the result as a memory size or offset operand.
RemediationAI
Apply the vendor-released patches immediately. For macOS deployments, update Microsoft Office 365 for Mac, Office LTSC for Mac 2021, and Office LTSC for Mac 2024 to version 16.111.26071215 or later. For Windows deployments, update Microsoft Office 2016 to version 16.0.5561.1000 or later. For Microsoft Office 2019, LTSC 2021, LTSC 2024, and Microsoft 365 Apps for Enterprise on Windows, apply the updates referenced at https://aka.ms/OfficeSecurityReleases as no single pinned version was independently enumerated in the EUVD data for those products. The authoritative Microsoft MSRC advisory is at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55057. As an interim workaround where patching is delayed, restrict the ability to open untrusted Office documents by enforcing Protected View and disabling macros via Group Policy, which reduces the attack surface by preventing automatic processing of document content from external sources - note this may impact legitimate document workflows.
Local code execution in Microsoft Word (and Office/SharePoint components that render Word content) stems from an integer
Arbitrary code execution in Microsoft Office Word (and the broader Office/365/SharePoint family) arises from a stack-bas
Local code execution in Microsoft Word (part of Microsoft 365 Apps, Office 2019, Office LTSC 2021/2024, and Office for M
Arbitrary code execution in Microsoft PowerPoint (and the broader Microsoft Office/365 suite on Windows and macOS) arise
Local code execution in Microsoft Office PowerPoint (including Microsoft 365 Apps, Office 2019, Office LTSC 2021/2024, a
Local code execution in Microsoft Office PowerPoint (CWE-122 heap-based buffer overflow) lets an unauthorized attacker r
Local code execution in Microsoft Word (and the wider Microsoft Office / Microsoft 365 Apps family) lets an unauthorized
Local code execution in Microsoft Word (Office 2016/2019, Microsoft 365 Apps, Office LTSC 2021/2024) arises from a heap-
Local code execution in Microsoft Office Word (CWE-416 use-after-free) allows an unauthorized attacker to run arbitrary
Local code execution in Microsoft Office Word (Microsoft 365 Apps, Office 2019/LTSC 2021/2024, Word 2016, and the macOS
Local code execution in Microsoft Office Word (via a stack-based buffer overflow, CWE-121) lets an attacker run arbitrar
Local code execution in Microsoft Office Word (across Microsoft 365 Apps, Office 2019/LTSC 2021/2024, Office for Mac, an
Same weakness CWE-190 – Integer Overflow or Wraparound
View allSame technique Integer Overflow
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External POC / Exploit Code
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