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PatchSiren cyber security CVE debrief

CVE-2026-81948 Microsoft CVE debrief

A heap-based buffer overflow vulnerability exists in Microsoft Office Excel, which could allow an unauthorized attacker to execute code locally. The CVE record was published on 2026-09-08T18:20:58.180Z and was last modified on 2026-09-17T20:18:40.880Z. The NVD entry is currently Analyzed. This vulnerability affects Microsoft Office Excel installations, and defenders should assess exposure and prioritize patching vulnerable systems. The vulnerability has a CVSS score of 7.8 and a severity of HIGH, indicating a high risk of exploitation.

Vendor
Microsoft
Product
Microsoft 365 Apps for Enterprise
CVSS
HIGH 7.8
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 should assess exposure and prioritize patching vulnerable systems. This includes operators, platform administrators, vulnerability management teams, and security teams who need to ensure that affected systems are patched to prevent potential local code execution.

Why it matters

Defenders should prioritize patching vulnerable Microsoft Office Excel installations to prevent potential local code execution. The vulnerability has a CVSS score of 7.8 and a severity of HIGH, indicating a high risk of exploitation. However, the CVE record and NVD detail page do not specify which versions are affected or provide details on exploitation, limiting the ability to assess the full impact.

  • Potential local code execution
  • Patching vulnerable systems to prevent exploitation
  • Verifying vendor-provided patches

Technical summary

A heap-based buffer overflow vulnerability exists in Microsoft Office Excel, which could allow an unauthorized attacker to execute code locally. The vulnerability has a CVSS score of 7.8 and a severity of HIGH. This vulnerability affects Microsoft Office Excel installations, and defenders should assess exposure and prioritize patching vulnerable systems. The CVE record and NVD detail page provide information about the vulnerability, but do not specify which versions are affected or provide details on exploitation.

Defensive priority

Defenders should prioritize patching vulnerable Microsoft Office Excel installations to prevent potential local code execution.

Recommended defensive actions

  • Patch vulnerable Microsoft Office Excel installations
  • Verify and apply vendor-provided patches
  • Monitor for potential exploitation attempts

Evidence notes

The CVE record and NVD detail page provide information about the vulnerability, but do not specify which versions are affected or provide details on exploitation.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-81948 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-81948

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

  • CVE-2026-81948 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-81948

    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.