EUVD-2026-56575
GHSA-xv49-v556-j4m7
Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Local vector confirmed by description; user interaction required to open crafted file; no integrity or availability impact; confidentiality fully compromised on vulnerable system.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
3DescriptionCVE.org
Improper input validation in Microsoft Office allows an unauthorized attacker to disclose information locally.
AnalysisAI
Local information disclosure in Microsoft Office stems from improper input validation (CWE-20), allowing a local attacker who can induce user interaction to read sensitive data from the affected system. Affected products span Microsoft 365 Apps for Enterprise, Office LTSC 2021/2024, Office 2019, and Office 365/LTSC for Mac, with Mac builds patched at 16.112.26081010 and Windows builds addressed via the Microsoft Office Security Releases channel. No public exploit has been identified at time of analysis, and SSVC rates exploitation as none with non-automatable attack path.
Technical ContextAI
The root cause is CWE-20 (Improper Input Validation), meaning Office fails to adequately validate or sanitize some form of input - likely a crafted document or data structure - before processing it, leading to out-of-bounds or unintended memory reads that expose confidential content. The local attack vector (AV:L) indicates the exploitation surface is confined to the local machine or a locally accessible file, rather than a network-reachable service. The CVSS UI:R component confirms a user must open or interact with a malicious file. Affected CPE scope covers seven distinct product lines: Microsoft Office 365 for Mac, Microsoft 365 Apps for Enterprise (Windows), Microsoft Office LTSC for Mac 2021 and 2024, Microsoft Office LTSC 2021 and 2024 (Windows), and Microsoft Office 2019, indicating the vulnerable parsing or input-handling code is shared across the Office suite codebase.
RemediationAI
The primary fix is to apply the vendor-released patch: for Mac-based Office products (Office 365 for Mac, Office LTSC for Mac 2021/2024), update to version 16.112.26081010 or later via Microsoft AutoUpdate or the Mac App Store. For Windows-based products (Microsoft 365 Apps for Enterprise, Office LTSC 2021/2024, Office 2019), apply the update available through the Microsoft Office Security Releases channel at https://aka.ms/OfficeSecurityReleases, or deploy via Windows Update/WSUS/Microsoft Endpoint Manager. Organizations that cannot patch immediately should consider restricting opening of untrusted Office documents (e.g., enforcing Protected View for all externally sourced files, which is a built-in Office control that limits code and parser execution for untrusted content), noting that Protected View may impact document editing workflows. Disabling macros via Group Policy does not mitigate this vulnerability, as the flaw is in input validation rather than macro execution. The vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70314 should be consulted for the definitive patch mapping.
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Same weakness CWE-20 – Improper Input Validation
View allSame technique Information Disclosure
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External POC / Exploit Code
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