CVE-2026-45463: Microsoft Office Remote Code Execution Vulnerability

highCVSS 8.4CVE-2026-45463

Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.

CSIRTS triage

vendor: Microsoft product: Office Remote code execution

What: Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
Who is affected: Users of Microsoft Office.
Urgency: Remediation is high urgency due to the potential for remote code execution.
Action: Update Microsoft Office to the latest version.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 8.4
Published: 2026-06-09
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45463

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-454630.34% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 26% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-45463	coverage & exploitation status	NVD · CVE.org

Recent advisories for Microsoft Office Remote

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-44819: Microsoft Office Remote Code Execution Vulnerabilitymsrc · 2026-06-09
highCVE-2026-45474: Microsoft Office Remote Code Execution Vulnerabilitymsrc · 2026-06-09
highCVE-2026-45645: Microsoft Office Remote Code Execution Vulnerabilitymsrc · 2026-06-09
highCVE-2026-45472: Microsoft Office Remote Code Execution Vulnerabilitymsrc · 2026-06-09
highCVE-2026-45475: Microsoft Office Remote Code Execution Vulnerabilitymsrc · 2026-06-09
highCVE-2026-44824: Microsoft Office Remote Code Execution Vulnerabilitymsrc · 2026-06-09