Heap-based buffer overflow in Microsoft Office - CVE-2026-70220
Published: October 14, 2026
Vulnerability identifier: #VU154653
CSH Severity: High
CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-70220
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code locally.
The vulnerability exists due to a heap-based buffer overflow in Microsoft Office Word when processing a malicious Office file. A remote attacker can send a malicious Office file and convince the victim to open it to execute arbitrary code locally.
The Preview Pane is not an attack vector for this vulnerability.
Affected software
Microsoft Office
How to mitigate CVE-2026-70220
Install security update from vendor's website.
Microsoft Office - addressed in versions 16.0.14334.20974, 16.0.17932.21056