Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessGain low-privileged local access
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DeliverySupply crafted Word input
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ExploitOverflow stack buffer (CWE-121)
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ExecutionHijack control flow and execute code
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ImpactElevate to higher privileges
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Stack buffer bounds checking
MITRE ATT&CK
1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Requires a local, already-authorized/authenticated user on a host running an affected build of Microsoft Office Word - specifically Office LTSC 2021/2024, Office LTSC for Mac 2021/2024, Microsoft 365 Apps for Enterprise, or Office 365 for Mac below the fixed builds (e.g. LTSC 2021 <16.0.14334.20974, LTSC 2024 <16.0.17932.21056). Exploitation is local only (AV:L) and cannot be performed remotely or by an unauthenticated actor (PR:L). Limiting factors: the attacker must already hold valid low-level access to the machine, and a patched Office build fully removes the flaw. Note the description implies privilege elevation via Word's handling of crafted input; although the supplied vector states UI:N, Office memory-corruption flaws commonly require the victim to open a malicious document, which would be an additional limiting condition if confirmed by Microsoft. |
| Impact | The provided CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, base 7.8 HIGH) describes a local, low-complexity elevation-of-privilege flaw requiring only low privileges (an authenticated/authorized local user) and no user interaction, yielding full confidentiality, integrity, and availability impact on the host. No EPSS score is supplied, so exploitation probability cannot be quantified. The CVE is not listed in CISA KEV and no public POC is referenced, so the exploitation status is: no public exploit identified at time of analysis. SSVC inputs (exploitation=none observed, automatable=no given local vector, technical impact=total) point to a real but not emergency priority: this is a genuine privilege-escalation primitive in ubiquitous software with a vendor patch, warranting prompt patching, but there is no current evidence of mass or automated exploitation. One signal worth verifying: the description frames this as an elevation of privilege via a stack buffer overflow in Word, yet the vector asserts UI:N - most Office memory-corruption bugs require a user to open a crafted document (UI:R). This UI:N/EoP combination is unusual and should be verified against the Microsoft advisory; if user interaction is in fact required, realistic risk is lower than the vector implies. |
| Exploit ScenarioDerived | A low-privileged but authenticated local user on a Windows (or macOS) host with Microsoft Office Word installed triggers a crafted condition that overflows a stack buffer in Word's processing code, corrupting the stack to hijack control flow and run attacker-controlled code at a higher privilege level. The result is local privilege escalation to full host compromise. No public exploit code is identified at time of analysis. |
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Alert meAnalysisAIv1 – Oct 13, 2026
Stack-based buffer overflow in Microsoft Office Word enables a local, authenticated user to elevate privileges to the level of the affected process, resulting in high confidentiality, integrity, and availability impact on the host (CVSS 3.1 base 7.8 HIGH). Affected builds include Microsoft Office LTSC 2021 before 16.0.14334.20974, Office LTSC 2024 before 16.0.17932.21056, Microsoft 365 Apps for Enterprise, and Office LTSC/365 for Mac. A vendor patch is available; no public exploit code or confirmed active exploitation has been identified at time of analysis.
RemediationAI
Vendor-released patch: apply the Microsoft Office security updates that raise affected builds to at least Office LTSC 2021 16.0.14334.20974 and Office LTSC 2024 16.0.17932.21056; for Microsoft 365 Apps for Enterprise and Mac/Office 365 for Mac channels, install the latest updates per https://aka.ms/OfficeSecurityReleases and the MSRC advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-96995. Because exploitation requires an attacker who already holds low-level local access, the most effective compensating controls are to enforce least privilege by removing local administrator rights from standard users and to use application control (e.g., Windows Defender Application Control or AppLocker) to prevent unpatched Office binaries from executing-though these measures can disrupt legitimate workflows and require careful policy testing. If patching is delayed, restrict interactive logon to trusted personnel and consider Attack Surface Reduction rules that block Office applications from creating child processes, which may reduce but not eliminate the elevation path and can break legitimate Office automation.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 2 packages in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
CWE-121 (Stack-based Buffer Overflow) in Microsoft Office Word's handling of crafted input causes memory corruption that a low-privileged local attacker can leverage to execute code with elevated privileges. The vulnerability is local (AV:L) with low attack complexity (AC:L) and requires low privileges (PR:L), matching an authenticated local user; the provided vector lists UI:N, though Office memory-corruption flaws commonly require the victim to open a malicious document, which would add a user-interaction precondition if confirmed by Microsoft. Affected products per EUVD include Office LTSC 2021 (16.0.1 <16.0.14334.20974), Office LTSC 2024 (16.0.0 <16.0.17932.21056), Microsoft 365 Apps for Enterprise (16.0.1), Office LTSC for Mac 2021/2024, and Office 365 for Mac 1.0.0, all below vendor-fixed builds. Successful exploitation yields full control over the host's confidentiality, integrity, and availability (C:H/I:H/A:H).
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Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Local authorized user (AV:L, PR:L), straightforward stack overflow (AC:L), total host impact (C/I/A:H); UI:N retained per vendor though document-open interaction is plausible.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
2DescriptionCVE.org
Stack-based buffer overflow in Microsoft Office Word allows an authorized attacker to elevate privileges locally.
Executive ViewAI
A high-severity local privilege escalation vulnerability in Microsoft Office Word affects multiple Office versions deployed across the organization, including LTSC 2021, LTSC 2024, Microsoft 365 Apps for Enterprise, and Office LTSC/365 for Mac. An attacker with local access could exploit this flaw to gain elevated privileges, potentially compromising sensitive data and system integrity. No public exploit has been identified, but a vendor patch is available and should be applied promptly to mitigate risk.
Apply vendor patch.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
A stack-based buffer overflow occurs when a program writes more data to a buffer located on the stack than it was allocated to hold.
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EUVD-2026-99800
GHSA-5j52-6gp9-vxj8
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB