PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-81395 Microsoft CVE debrief

Microsoft Office Excel is vulnerable to an out-of-bounds read, allowing local information disclosure. The CVE record was published on 2026-09-08T18:20:56.023Z and has not been modified since then. The NVD entry is currently Analyzed. Defenders responsible for Microsoft Office Excel installations, particularly in local threat contexts, should assess exposure and apply patches or updates to address the vulnerability. This vulnerability has a MEDIUM severity and a CVSS score of 5.5, indicating a moderate risk. The vulnerability allows an unauthorized attacker to disclose information locally, which could lead to further exploitation. It is essential to verify affected versions and take

Vendor
Microsoft
Product
Microsoft 365 Apps for Enterprise
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-08
Original CVE updated
2026-09-17
Advisory published
2026-09-08
Advisory updated
2026-09-17

Who should care

Defenders responsible for Microsoft Office Excel installations, particularly in local threat contexts, should assess exposure and apply patches or updates to address the vulnerability.

Why it matters

CVE-2026-81395 is a MEDIUM-severity vulnerability in Microsoft Office Excel that allows local information disclosure. Defenders should assess exposure, prioritize remediation, and apply patches or updates to address the vulnerability.

  • Local information disclosure possible due to out-of-bounds read vulnerability
  • Requires verification of affected versions and application of patches or updates
  • Defenders need to assess exposure and prioritize remediation for Microsoft Office Excel installations

Technical summary

The vulnerability is an out-of-bounds read in Microsoft Office Excel, which could allow an unauthorized attacker to disclose information locally. The CVSS score is 5.5, and the severity is MEDIUM. This vulnerability affects Microsoft Office Excel installations and requires verification of affected versions and application of patches or updates. The vulnerability can be exploited locally, and defenders need to assess exposure and prioritize remediation for Microsoft Office Excel installations. The CVE record and NVD entry provide details on the vulnerability, but

Defensive priority

Assess exposure and apply patches for Microsoft Office Excel

Recommended defensive actions

  • Inventory and assess Microsoft Office Excel installations for potential exposure
  • Apply patches or updates provided by Microsoft to address the vulnerability
  • Monitor for any suspicious activity related to Microsoft Office Excel

Evidence notes

The CVE record and NVD entry provide details on the vulnerability. However, specific version information and remediation steps require verification from official sources.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-81395 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-81395

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-81395 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-81395

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.