CVE-2026-97739

8.8High

Published 13 Oct 2026 · NVD status: Analyzed · AI triage by gemini-3.8-flash

8.8High

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Required
Impact: Full C/I/A compromise
Weakness: CWE-122, CWE-191

Impact

Remote attackers can execute arbitrary code on the victim's system, but they require a user to open a malicious Excel spreadsheet first.

Root cause

An integer underflow condition triggers a heap-based buffer overflow during Excel file parsing.

Affected systems

Versions not listed — check the vendor advisory.

CVSS v3.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Fix & remediation

Apply the official patch from the MSRC advisory via Microsoft Update, or block untrusted Excel attachments at the email gateway until systems are updated.

AI-suggested. Run it in staging first and check it against the vendor advisory. Why?

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NVD description

Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97739PatchVendor Advisory

Source: nvd.nist.gov/vuln/detail/CVE-2026-97739