Microsoft Office Word Information Disclosure Vulnerability
Priority LOW 25CWE-125Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, Red Hat and Microsoft. Impact type from Microsoft.
Summary
Off-by-one error in Microsoft Office Word allows an unauthorized attacker to disclose information locally.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00435 38th percentileScored 2026-11-07
Fix Fixed Red Hat: 2 advisoriesMicrosoft: 1 update
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Microsoft | Microsoft 365 Apps for Enterprise | 16.0.1 to before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases | Patch available | CNA |
| Microsoft | Microsoft Office 2019 | 19.0.0 to before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases | Patch available | CNA |
| Microsoft | Microsoft Office LTSC 2021 | 16.0.1 to before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases | Patch available | CNA |
| Microsoft | Microsoft Office LTSC 2024 | 16.0.0 to before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases | Patch available | CNA |
| Microsoft | Microsoft Word 2016 | 16.0.1 to before 16.0.5565.1000 | 16.0.5565.1000 | Patch available | CNA |
- Microsoft 365 Apps for Enterprise VendorMicrosoft Affected 16.0.1 to before https://aka.ms/OfficeSecurityReleases Fixed in https://aka.ms/OfficeSecurityReleases Patch available CNA
- Microsoft Office 2019 VendorMicrosoft Affected 19.0.0 to before https://aka.ms/OfficeSecurityReleases Fixed in https://aka.ms/OfficeSecurityReleases Patch available CNA
- Microsoft Office LTSC 2021 VendorMicrosoft Affected 16.0.1 to before https://aka.ms/OfficeSecurityReleases Fixed in https://aka.ms/OfficeSecurityReleases Patch available CNA
- Microsoft Office LTSC 2024 VendorMicrosoft Affected 16.0.0 to before https://aka.ms/OfficeSecurityReleases Fixed in https://aka.ms/OfficeSecurityReleases Patch available CNA
- Microsoft Word 2016 VendorMicrosoft Affected 16.0.1 to before 16.0.5565.1000 Fixed in 16.0.5565.1000 Patch available CNA
CPE configurations NVD · 10
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x64:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x86:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x64:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x86:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x64:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x86:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:word:2016:*:*:*:*:*:x64:* | 2016 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:word:2016:*:*:*:*:*:x86:* | 2016 | Vulnerable | Microsoft |
- cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x64:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x86:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x64:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x86:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x64:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x86:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:word:2016:*:*:*:*:*:x64:* Versions 2016 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:word:2016:*:*:*:*:*:x86:* Versions 2016 Vulnerable ·Microsoft
Remediation
Red Hat 2 advisories
- RHSA-2026:60387 Released 2026-08-26 · Red Hat rating ImportantRed Hat Advanced Cluster Management for Kubernetes v2.11.11 security update
- Red Hat Advanced Cluster Management for Kubernetes 2.11 registry.redhat.io/rhacm2/acm-governance-policy-addon-controller-rhel9, registry.redhat.io/rhacm2/acm-must-gather-rhel9, registry.redhat.io/rhacm2/acm-prometheus-config-reloader-rhel9 +24
- RHSA-2026:59579 Released 2026-08-25 · Red Hat rating Importantmulticluster engine for Kubernetes v2.6.14 security update
- multicluster engine for Kubernetes 2.6 registry.redhat.io/multicluster-engine/addon-manager-rhel9, registry.redhat.io/multicluster-engine/cluster-curator-controller-rhel9, registry.redhat.io/multicluster-engine/cluster-image-set-controller-rhel9 +17
Microsoft 1 update
- Security Update
- Microsoft Word 2016 (32-bit edition) 16.0.5565.1000
- Microsoft Word 2016 (64-bit edition) 16.0.5565.1000
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Advanced Cluster Management for Kubernetes 2.11 | Fixed | RHSA-2026:60387 |
| multicluster engine for Kubernetes 2.6 | Fixed | RHSA-2026:59579 |
Not affected: 2 products
- Red Hat Advanced Cluster Management for Kubernetes 2.11
- multicluster engine for Kubernetes 2.6
Microsoft
Microsoft's page for this CVE →
- Impact
- Information Disclosure
- Exploited
- No
- Publicly disclosed
- No
- Exploitability
- Exploitation Less Likely
| Product | Status | Plan or fix |
|---|---|---|
| Microsoft 365 Apps for Enterprise for 32-bit Systems | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft 365 Apps for Enterprise for 64-bit Systems | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft Office 2019 for 32-bit editions | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft Office 2019 for 64-bit editions | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft Office LTSC 2021 for 32-bit editions | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft Office LTSC 2021 for 64-bit editions | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft Office LTSC 2024 for 32-bit editions | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft Office LTSC 2024 for 64-bit editions | Fixed | https · //aka.ms/OfficeSecurityReleases |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-66806
- 2026-10-03 Alias added: GHSA-vr2p-489v-8hm2
References
More Microsoft 365 Apps vulnerabilities
- TI-2024-14173 Microsoft Outlook Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2023-09240 Microsoft Outlook Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2024-25471 Microsoft Project Remote Code Execution Vulnerability KEVCVSS 3.1HIGH 8.8
- TI-2023-17652 Microsoft Outlook Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
- TI-2026-17368 Microsoft Word Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 7.8
- TI-2026-17363 Microsoft Office Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 7.8
Sources
- CVE-2026-66806 · CVE Program
- CVE-2026-66806 · NVD
- FIRST EPSS
- GHSA-vr2p-489v-8hm2 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-66806 · Microsoft Security Update Guide
- CVE-2026-66806 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences