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PatchSiren cyber security CVE debrief

CVE-2026-78514 Microsoft CVE debrief

A use-after-free vulnerability in Microsoft Office Word allows an unauthorized attacker to execute code over a network. This CVE was published on 2026-09-08T18:20:46.720Z and was last modified on 2026-09-17T20:18:32.057Z. The NVD entry is currently Analyzed. The vulnerability has a CVSS score of 8.8 and is considered HIGH severity. Defenders should prioritize verifying exposure of Microsoft Office Word installations, especially in network-connected environments, and apply patches as soon as possible to prevent potential code execution.

Vendor
Microsoft
Product
Microsoft 365 Apps for Enterprise
CVSS
HIGH 8.8
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 Word installations, especially in network-connected environments, should assess exposure and prioritize patching.

Why it matters

Defenders should prioritize verifying exposure of Microsoft Office Word installations, especially in network-connected environments, and apply patches as soon as possible to prevent potential code execution.

  • Verify exposure of Microsoft Office Word installations to prioritize patching.
  • Assess network configurations to limit potential attack surfaces.
  • Monitor for suspicious activity related to Microsoft Office Word.
  • Apply patches as soon as possible to prevent potential code execution.

Technical summary

The CVE record describes a use-after-free vulnerability in Microsoft Office Word that allows an unauthorized attacker to execute code over a network. The vulnerability has a CVSS score of 8.8 and is considered HIGH severity. The CVE record and NVD detail page provide information on the vulnerability, but do not specify versions or provide remediation details.

Defensive priority

Defenders should prioritize verifying exposure of Microsoft Office Word installations, especially in network-connected environments, and apply patches as soon as possible.

Recommended defensive actions

  • Verify exposure of Microsoft Office Word installations, especially in network-connected environments.
  • Apply patches as soon as possible.
  • Review network configurations to limit potential attack surfaces.
  • Monitor for suspicious activity related to Microsoft Office Word.

Evidence notes

The CVE record and NVD detail page provide information on the vulnerability, but do not specify versions or provide remediation details. The Microsoft patch advisory is referenced, but its contents are not provided.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-78514 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-78514

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

  • CVE-2026-78514 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-78514

    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.