High severity8.8NVD Advisory· Published Sep 8, 2026· Updated Sep 17, 2026
CVE-2026-78526
CVE-2026-78526
Description
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
Affected products
14- cpe:2.3:a:microsoft:microsoft_365:-:*:*:*:*:macos:*:*
cpe:2.3:a:microsoft:office_2016:-:*:*:*:-:*:x64:*+ 1 more
- cpe:2.3:a:microsoft:office_2016:-:*:*:*:-:*:x64:*
- cpe:2.3:a:microsoft:office_2016:-:*:*:*:-:*:x86:*
cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x64:*+ 7 more
- cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x64:*
- cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x86:*
- cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x64:*
- cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x86:*
- cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:macos:-:*
- cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x64:*
- cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x86:*
- cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:macos:-:*
Patches
Vulnerability mechanics
References
1- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78526nvdPatchVendor Advisory
News mentions
3- Patch Tuesday - September 2026Rapid7 Blog · Sep 8, 2026
- Microsoft Office Word: 25 Memory Corruption Vulnerabilities Disclosed TogetherVypr Intelligence · Sep 8, 2026
- Massive Microsoft Patch Tuesday September 2026 – 973 Vulnerabilities Fixed, Including 2 Zero-DaysCyber Security News · Sep 8, 2026