CVE-2026-97769: microsoft 365_apps Heap-based Buffer Overflow

Vulnerability summary

CVE-2026-97769 is a high (CVSS 8.8) Heap-based Buffer Overflow vulnerability in microsoft 365_apps. EPSS estimates a 0.76% chance of exploitation in the next 30 days, higher than 54.3% of scored vulnerabilities.

Timeline

1. 13-10-2026
   PublishedVulnerability first disclosed.
2. 16-10-2026
   Last modifiedVulnerability information updated.

Description

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

• CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.