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TI-2026-21136 Aliases CVE-2026-26144GHSA-39m5-6xwx-6qjf

Microsoft Excel Information Disclosure Vulnerability

Priority MEDIUM 42CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
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. Impact type from Microsoft.

Summary

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01387 72nd percentileScored 2026-11-07
Fix Fixed Microsoft 365 Apps for Enterprise (Microsoft): https://aka.ms/OfficeSecurityReleases

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MicrosoftMicrosoft 365 Apps for Enterprise16.0.1 to before https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleasesPatch availableCNA
  • 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

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*not specified by NVDVulnerableMicrosoft
cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:*not specified by NVDVulnerableMicrosoft
  • 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

Remediation

  • Fix · CNA Microsoft 365 Apps for Enterprise (Microsoft) Fixed in https://aka.ms/OfficeSecurityReleases

Vendor assessments

Microsoft

Microsoft's page for this CVE →

Impact
Information Disclosure
Exploited
No
Publicly disclosed
No
Exploitability
Exploitation Unlikely
ProductStatusPlan or fix
Microsoft 365 Apps for Enterprise for 32-bit SystemsFixed https · //aka.ms/OfficeSecurityReleases
Microsoft 365 Apps for Enterprise for 64-bit SystemsFixed https · //aka.ms/OfficeSecurityReleases

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-26144
  2. 2026-10-03 Alias added: GHSA-39m5-6xwx-6qjf

References

  • 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
See all 935 →

Sources