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PatchSiren cyber security CVE debrief

CVE-2026-64906 Microsoft CVE debrief

Microsoft Access Remote Code Execution Vulnerability allows unauthorized attackers to execute code locally due to a heap-based buffer overflow in Microsoft Office Access. This vulnerability, with a CVSS score of 7.8 and HIGH severity, impacts Microsoft Office and Microsoft 365 Apps for Enterprise deployments. Defenders responsible for these deployments should assess exposure and prioritize patching vulnerable versions to prevent potential local code execution. The CVE record and source item provide details on the vulnerability, but limited information is available on exploitation or affected versions beyond vendor advisories.

Vendor
Microsoft
Product
Microsoft 365 Apps for Enterprise
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-11
Original CVE updated
2026-10-08
Advisory published
2026-08-11
Advisory updated
2026-10-08

Who should care

Defenders responsible for Microsoft Office and Microsoft 365 Apps for Enterprise deployments should assess exposure and prioritize patching vulnerable versions.

Why it matters

CVE-2026-64906 is a high-severity vulnerability in Microsoft Access and Microsoft 365 Apps for Enterprise that allows local code execution via heap-based buffer overflow. Defenders should prioritize patching vulnerable versions and inventory deployments to prevent potential exploitation.

  • Potential local code execution by unauthorized attackers
  • Need to verify and patch vulnerable Microsoft Office and Microsoft 365 Apps for Enterprise versions
  • Inventory and monitoring of Microsoft Access and Microsoft 365 Apps for Enterprise versions required

Technical summary

A heap-based buffer overflow in Microsoft Office Access allows an unauthorized attacker to execute code locally, with CVSS score of 7.8 and HIGH severity. This vulnerability impacts Microsoft Office and Microsoft 365 Apps for Enterprise deployments. Defenders should prioritize patching vulnerable versions and inventory deployments to prevent potential exploitation. The vulnerability is detailed in the CVE record and source item, with additional information available in vendor advisories.

Defensive priority

Defenders should prioritize patching vulnerable Microsoft Office and Microsoft 365 Apps for Enterprise versions to prevent potential local code execution.

Recommended defensive actions

  • Patch vulnerable Microsoft Office and Microsoft 365 Apps for Enterprise versions
  • Inventory and verify versions of Microsoft Access and Microsoft 365 Apps for Enterprise
  • Monitor for updates from Microsoft regarding CVE-2026-64906

Evidence notes

The CVE record and source item provide details on the vulnerability, but limited information is available on exploitation or affected versions beyond vendor advisories.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-64906 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-64906

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

  • CVE-2026-64906 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-64906

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

Supplemental references

  • Microsoft Access Remote Code Execution Vulnerability

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/64xxx/CVE-2026-64906.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64906

    Supplemental source - vendor-advisory, patch

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.