SB2026101481 - Two vulnerabilities in Microsoft Excel

Description

This security bulletin contains information about 2 vulnerabilities.

1) Use-after-free (CVE-ID: CVE-2026-97743)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to read portions of process memory.

The vulnerability exists due to use-after-free in Microsoft Office Excel when processing a malicious Office file. A remote attacker can send a user a malicious Office file and convince them to open it to read portions of process memory.

The Preview Pane is not an attack vector.

2) Heap-based buffer overflow (CVE-ID: CVE-2026-97741)

CWE-ID: CWE-122 - Heap-based Buffer Overflow

CVSSv4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a heap-based buffer overflow in Microsoft Office Excel when processing a malicious Office file. A remote attacker can send a malicious Office file to a user and convince them to open it to execute arbitrary code.

The Preview Pane is not an attack vector for this vulnerability.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-97743
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-97741