CVE-2026-77902 Microsoft Office Excel - Remote Code Execution

Microsoft Office Excel contains a heap-based buffer overflow caused by improper memory handling, letting unauthorized attackers execute code remotely, exploit requires network access.

CVSS base score 8.8 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.80% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Remote Code Execution
Impact
Remote Code Execution
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published
13 October 2026
Updated
15 October 2026
Weakness
CWE-122

Vendor fix

Update to the latest version of Microsoft Office Excel.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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