Is CVE-2026-26109 actively exploited?

CVE-2026-26109 has no public evidence of in-the-wild exploitation as of 2026-03-13.

What is the CVSS score for CVE-2026-26109?

CVE-2026-26109 has a CVSS score of 8.4 (HIGH severity). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

How do I patch CVE-2026-26109?

Patch guidance is available from microsoft security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-26109.

Fix CVE-2026-26109 - HIGH microsoft 365 apps

Q: Which products are affected by CVE-2026-26109?

13 products: microsoft 365 apps, microsoft 365 apps, microsoft excel, microsoft excel, microsoft office, and 8 more.

Description

Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

CVSS Metrics

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector: local
Complexity: low
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Weaknesses: CWE-125 · Out-of-bounds Read

Metadata

Primary Vendor: MICROSOFT
Published: 3/10/2026
Last Modified: 3/13/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

microsoft : 365_appsmicrosoft : 365_appsmicrosoft : excelmicrosoft : excelmicrosoft : officemicrosoft : officemicrosoft : office_long_term_servicing_channelmicrosoft : office_long_term_servicing_channelmicrosoft : office_long_term_servicing_channelmicrosoft : office_long_term_servicing_channelmicrosoft : office_long_term_servicing_channelmicrosoft : office_long_term_servicing_channelmicrosoft : office_online_server

Remediation Guidance

Executive Summary

View on NIST NVD