What is the CVSS score of EUVD-2026-44200?

EUVD-2026-44200 has a contested CVSS base score of 7.8 from a third party (e.g. CISA-ADP), while the vendor rates it High. vuln.today uses the vendor rating as authoritative.

Which versions of Microsoft Office Word are affected by EUVD-2026-44200?

Microsoft Office Word and Office 365 are vulnerable to arbitrary code execution when users open malicious documents, potentially compromising user endpoints and enabling lateral movement across the…. A patch is available.

How to fix or mitigate EUVD-2026-44200?

Within 24 hours, inventory all Microsoft Office and Office 365 installations across the organization and classify by user criticality; verify the latest MSRC patch is available in your patch management system and stage for deployment. Within 7 days, deploy the Microsoft Office patch released through MSRC to all production systems beginning with high-risk user populations (executives, finance, engineering), and implement email gateway filtering to block Office attachments from external sources during remediation. Within 30 days, achieve 100% patch compliance across all Office installations and deploy endpoint detection monitoring to identify any exploitation attempts targeting this vulnerability.

Microsoft Office Word EUVD-2026-44200

| CVE-2026-55038 HIGH

Stack-based Buffer Overflow (CWE-121)

2026-07-14 microsoft

GHSA-x639-3674-v6hc

Buffer Overflow Microsoft Stack Overflow Microsoft Sharepoint Enterprise Server 2016 Microsoft Sharepoint Server 2019 Microsoft Sharepoint Server Subscription Edition Microsoft 365 Apps For Enterprise Microsoft Office Ltsc 2024 Microsoft Office 2019 Microsoft Office Ltsc 2021 Microsoft Office Ltsc For Mac 2021 Microsoft Office Ltsc For Mac 2024 Microsoft Word 2016 Microsoft Office 365 For Mac

High

Disputed · 7.8 Vendor: microsoft

Temporal: 6.8

Severity by source

Sources disagree (Medium–Critical)

Vendor (microsoft) PRIMARY

7.8 HIGH

AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

ENISA EUVD

CRITICAL

qualitative

CIRCL (temporal)

6.8 MEDIUM

cvss

vuln.today AI

7.8 HIGH

Malicious file must be opened locally (AV:L, UI:R) with no prior auth (PR:N); memory-corruption RCE gives full C/I/A in the user's process (scope unchanged).

3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

4.0 AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.

CVSS VectorVendor: microsoft

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Jul 14, 2026 - 19:27 vuln.today

CVE Published

Jul 14, 2026 - 17:08 nvd

HIGH 7.8

DescriptionCVE.org

Stack-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code locally.

AnalysisAI

Arbitrary code execution in Microsoft Office Word (and the broader Office/365/SharePoint family) arises from a stack-based buffer overflow (CWE-121) that an attacker triggers when a victim opens a maliciously crafted document. The CVSS 3.1 vector (AV:L/UI:R) confirms this is a file-borne, local-context flaw requiring the user to open attacker-supplied content, yielding full confidentiality, integrity, and availability impact in the user's session. No public exploit identified at time of analysis, and it is not listed in CISA KEV; Microsoft has released a patch via MSRC.

Technical ContextAI

The root cause is CWE-121, a stack-based buffer overflow, occurring in Word's parsing of document content where a fixed-size stack buffer is written beyond its bounds, corrupting adjacent stack memory including saved return addresses or structured exception handlers. The CPE data shows the affected code is shared across the Office ecosystem - Microsoft 365 Apps for Enterprise, Office 2019, Office LTSC 2021/2024, the Mac editions (Office 365 for Mac, Office LTSC for Mac 2021/2024), Word 2016, and even SharePoint Enterprise Server 2016, SharePoint Server 2019, and SharePoint Server Subscription Edition, indicating the vulnerable Word document-parsing component is reused server-side by SharePoint for document handling. Successful overflow of the stack allows redirection of execution flow to attacker-controlled code within the process running Word or the SharePoint document parser.

RemediationAI

Patch available per vendor advisory - apply Microsoft's security update for each affected channel as documented at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55038 (exact fixed build numbers are not included in the provided data and should be taken from that MSRC page). For Office/365/Word clients, ensure Microsoft Update or the relevant Click-to-Run/LTSC servicing channel is applied, and for the Mac editions update via Microsoft AutoUpdate. For SharePoint servers, apply the corresponding server-side update. Where immediate patching is not possible, reduce exposure by opening untrusted documents in Protected View and keeping it enabled (trade-off: users may disable it to edit), blocking or quarantining Office documents from external email and web sources at the gateway, and enabling Attack Surface Reduction rules that constrain Office child-process creation (trade-off: possible false positives for legitimate macro-driven workflows); for SharePoint, restrict document upload/processing to trusted users pending patching.