No exploitation reported

CVE-2026-40364

No exploitation reported by the sources we read.

Published2026-05-12
WeaknessCWE-122 · CWE-843 · CWE-908

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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

Timeline

dates in UTC

2026-05-1218:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-25 15:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-40364?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-40364?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Microsoft office long term servicing channel

Branch	Affected	Fixed in	Source
2021.x	= 2021	no fix published	NVD
2024.x	= 2024	no fix published	NVD

Microsoft 365 apps

Branch	Affected	Fixed in	Source
—	all versions	no fix published	NVD

Microsoft office

Branch	Affected	Fixed in	Source
2019.x	= 2019	no fix published	NVD

1 more product in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

msrc.microsoft.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVE recordread 2026-10-23
CISA-ADPSSVC decisionnone2026-05-13
OpenCVESSVC decisionnone—
CNACVSS 3.18.4read 2026-10-23
CNAweakness (CWE)CWE-122, CWE-843, CWE-908read 2026-10-23
FIRST EPSSEPSS score4.4 %2026-10-25
Microsoft MSRCadvisory—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2026-05-12
Last Modified: 2026-06-17
NVD status: Analyzed
MSRC Title: Microsoft Word Remote Code Execution Vulnerability

Frequently asked questions

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.

Is CVE-2026-40364 actively exploited?

Active exploitation of CVE-2026-40364 has not been confirmed. Its EPSS score was 4.4% on 2026-10-25, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-40364?

CVE-2026-40364 has a CVSS v3 base score of 8.4 (HIGH severity), with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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