Threat Intelligence / CVE / CVE-2026-40364

CVE-2026-40364 — Microsoft 365 Apps for Enterprise

CVSS v3.1 8.4 (HIGH) · EPSS 0.1% (higher than 40.9% of all scored CVEs) · Priority 5.8/10 · Published 2026-05-12

As of 2026-05-26, CVE-2026-40364 is a HIGH-severity vulnerability in Microsoft 365 Apps for Enterprise, CVSS v3.1 8.4, EPSS 0.1% (40.9th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-40364, most recently “Microsoft May 2026 Patch Tuesday — 137 CVEs, 31 Critical (16 RCE) Including CVE-2026-41089 Pre-Auth Netlogon Stack Overflow on Domain Controllers”.

Last updated: 2026-05-26

What is CVE-2026-40364?

Access of resource using incompatible type ('type confusion') in Microsoft Office Word allows an unauthorized attacker to execute code locally.

The record classifies CVE-2026-40364 under weakness classes CWE-843, CWE-908, CWE-122. Its CVSS v3 base vector states that the flaw requires local access to the host, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 7 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 123 days ago.

Severity and exploitation probability

CVSS v3.1 base score
8.4 — HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
EPSS (FIRST)
0.1% probability of exploitation in the next 30 days, higher than 40.9% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
5.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-05-12, last modified 2026-05-26

Is CVE-2026-40364 being exploited?

It currently carries a trending score of 15 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-40364

No vendor patch reference has been recorded for CVE-2026-40364 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-40364

1 tracked threat in the Threadlinqs corpus references CVE-2026-40364, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Seeded from cveorg and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

Full detection coverage & IOCs for threats exploiting CVE-2026-40364 are available via the Threadlinqs MCP server (Purple tier). View plans →

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