Out-of-bounds read in Microsoft Office for macOS and Microsoft Word - CVE-2026-66809
Published: August 12, 2026
Vulnerability identifier: #VU141988
CSH Severity: Low
CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-66809
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to out-of-bounds read in Microsoft Office graphics component when parsing a specially crafted file. A remote attacker can trick the victim into opening a crafted file to disclose sensitive information.
The Preview Pane is not an attack vector for this vulnerability.
Affected software
Microsoft Office for macOS
Microsoft Word
Microsoft Word
How to mitigate CVE-2026-66809
Install security update from vendor's website.
Microsoft Office for macOS - update to 16.112.26081010
Microsoft Word - update to 16.0.5565.1000
Microsoft Word - update to 16.0.5565.1000