CVE-2026-81393 Microsoft CVE debrief

Who should care

Defenders responsible for Microsoft Office Excel installations should assess exposure and prioritize verification of vulnerable versions. Security teams and vulnerability management teams should review the CVE Program record and NVD entry for details on the vulnerability. Operators of Microsoft Office Excel installations should apply patches if available to prevent potential information disclosure.

Why it matters

CVE-2026-81393 is a MEDIUM-severity vulnerability in Microsoft Office Excel that allows unauthorized attackers to disclose information locally. Defenders should assess exposure, prioritize verification of vulnerable versions, and apply patches if available to prevent potential information disclosure.

• Assess exposure of Microsoft Office Excel installations
• Prioritize verification of vulnerable versions
• Apply patches if available to prevent potential information disclosure

Technical summary

Microsoft Office Excel is vulnerable to an out-of-bounds read, allowing unauthorized attackers to disclose information locally. The vulnerability has a CVSS score of 5.5 and is classified as MEDIUM severity. The vulnerability affects Microsoft Office Excel installations. Defenders should assess exposure and prioritize verification of vulnerable versions. The CVE Program record and NVD entry provide details on the vulnerability.

Defensive priority

Assess exposure of Microsoft Office Excel installations, prioritize verification of vulnerable versions, and apply patches if available.

Recommended defensive actions

• Assess exposure of Microsoft Office Excel installations
• Prioritize verification of vulnerable versions
• Apply patches if available
• Monitor for potential information disclosure

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, but information on exploitation and impact is limited. There is no evidence of exploitation in the wild. The CVE Program record and NVD entry are the primary sources of information. Defenders should verify vulnerable versions and apply patches if available. The vulnerability affects Microsoft Office Excel installations.

Sources and 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.