Buffer overflow in Microsoft 365 Apps For Enterprise

CVE-2026-77898

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

Vulnerability class: Buffer Overflow

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-77898?
CVE-2026-77898 is a high-severity vulnerability in Microsoft 365 Apps For Enterprise, classified under Heap-based Buffer Overflow. CVSS score: 7.5/10. Published 2026-09-08.
How severe is CVE-2026-77898?
High severity. CVSS v3 base score is 7.5 out of 10.