CVE-2026-42831

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

Score

CVSS 3.1 7.8 High

Status

Analyzed - secure@microsoft.com

Published

2026-05-12

Last modified

2026-10-26

Weaknesses

CWE-122

Affected products

• 365 Copilot (Microsoft)
• Office (Microsoft)
• Office Long Term Servicing Channel (Microsoft)
• Office Macos 2021 (Microsoft)
• Office Macos 2024 (Microsoft)

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42831