EUVD-2026-44153
GHSA-gm89-fgch-cv7q
Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Malicious file opened locally (AV:L) with required user interaction (UI:R), no prior privileges (PR:N), and memory corruption yielding full code execution gives C:H/I:H/A:H.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Lifecycle Timeline
2DescriptionCVE.org
Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
AnalysisAI
Local code execution in Microsoft Office Excel (across Microsoft 365 Apps for Enterprise, Office 2019, Office LTSC 2021/2024, and their macOS equivalents) arises from a use-after-free (CWE-416) memory-corruption flaw triggered when a user opens a maliciously crafted spreadsheet. The CVSS vector (AV:L/AC:L/PR:N/UI:R) indicates an unauthenticated attacker can achieve full confidentiality, integrity, and availability impact but requires the victim to open a file, making it a classic phishing-delivered client-side bug. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires the victim to open a specially crafted Excel document in an affected Office build (AV:L/AC:L/PR:N/UI:R), so the mandatory prerequisite is user interaction - opening or previewing the malicious spreadsheet - with no authentication or prior privileges on the target needed. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | CVSS is 7.8 (High) with a local attack vector (AV:L) that in Microsoft's model means the malicious content executes on the local machine after the user opens the file, combined with low complexity (AC:L), no privileges (PR:N), and required user interaction (UI:R). … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker emails a target a crafted Excel spreadsheet (e.g., disguised as an invoice or report); when the victim opens it in a vulnerable Office build, the use-after-free is triggered during parsing and attacker-controlled code runs in the context of the user. No public POC or active exploitation is identified at time of analysis, and the low attack complexity means a working exploit would reliably fire once the file is opened, but success hinges entirely on convincing the user to open the document. |
| Remediation | Patch available per vendor advisory: apply the Microsoft security update referenced at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47642 for each affected channel - Microsoft 365 Apps via Click-to-Run/monthly update, Office 2019 and LTSC 2021/2024 via Windows Update or the corresponding MSI/C2R build, the Mac editions via Microsoft AutoUpdate, and Office Online Server via its server update package; the input does not include an exact patched build number, so confirm the fixed version directly from the MSRC entry before deployment. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, issue security guidance to all Office users advising caution with unexpected spreadsheet attachments, and generate a complete inventory of affected systems including all Microsoft 365 and Office 2019/LTSC installations (Windows and macOS). …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
Local code execution in Microsoft Word (and Office/SharePoint components that render Word content) stems from an integer
Local code execution in Microsoft Office (2016, 2019, LTSC 2021/2024, Microsoft 365 Apps, and the macOS editions) arises
Arbitrary code execution in Microsoft Office Word (and the broader Office/365/SharePoint family) arises from a stack-bas
Local code execution in Microsoft Office (including Microsoft 365 Apps for Enterprise, Office 2016/2019, and Office LTSC
Local code execution in Microsoft Word (part of Microsoft 365 Apps, Office 2019, Office LTSC 2021/2024, and Office for M
Local arbitrary code execution in Microsoft Office (2016, 2019, LTSC 2021/2024, Microsoft 365 Apps for Enterprise, and O
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 Office (2016, 2019, LTSC 2021/2024, Microsoft 365 Apps for Enterprise, and Office for
Local code execution in Microsoft Office (2016, 2019, LTSC 2021/2024, Microsoft 365 Apps, and Office for Mac 2021/2024)
Same weakness CWE-416 – Use After Free
View allSame technique Use After Free
View allShare
External POC / Exploit Code
Leaving vuln.today