CVE-2026-55140
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk27th percentile - higher than 27% of all known CVEs
Summary
A heap-based buffer overflow vulnerability in Microsoft Office allows an unauthorized attacker to execute code locally. The issue stems from improper memory management when processing specially crafted files.
Risk Assessment
An attacker could gain full control over the victim's system, leading to data theft, malware installation, or further privilege escalation within the organization's network.
Recommendation
Apply security updates released by Microsoft for Office immediately. Restrict opening files from unknown sources and enforce least-privilege policies.
Other vulnerabilities in Microsoft Office
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Improper access control in Microsoft Office allows an unauthorized attacker to perform spoofing locally.
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Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
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A use after free vulnerability in Microsoft Office allows an authorized attacker to locally elevate privileges.
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Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
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Integer overflow or wraparound in Microsoft Office allows an authorized attacker to elevate privileges locally.
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Microsoft Office has a vulnerability related to resource access using an incompatible type ('type confusion'), allowing an unauthorized attacker to execute code locally.
- CVE-2026-20953High
Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.
- CVE-2026-20952High
Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.
- CVE-2026-20943High
An untrusted search path vulnerability in Microsoft Office allows an unauthorized attacker to execute code locally.
- CVE-2025-62557High
A use after free vulnerability in Microsoft Office allows an unauthorized attacker to execute code locally.
Original NVD description (English source)
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.