High severity7.5NVD Advisory· Published Sep 8, 2026· Updated Sep 17, 2026
CVE-2026-77898
CVE-2026-77898
Description
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code over a network.
Affected products
12(expand)+ 8 more
- (no CPE)
- 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:-:*
- cpe:2.3:a:microsoft:microsoft_365:-:*:*:*:*:macos:*:*
Patches
Vulnerability mechanics
References
1- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77898nvdPatchVendor Advisory
News mentions
5- Microsoft Patch Tuesday for September 2026 — Snort rules and prominent vulnerabilitiesCisco Talos Intelligence · Sep 8, 2026
- Patch Tuesday - September 2026Rapid7 Blog · Sep 8, 2026
- Microsoft Office: 22 Vulnerabilities Including RCE Flaws Disclosed TogetherVypr Intelligence · Sep 8, 2026
- Massive Microsoft Patch Tuesday September 2026 – 973 Vulnerabilities Fixed, Including 2 Zero-DaysCyber Security News · Sep 8, 2026
- September 2026 Patch Tuesday: Two Exploited Zero-Days and 113 Critical Vulnerabilities Among 972 CVEsCrowdStrike Blog