CVE-2026-40366

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.38% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 31.4% of scored records. A rank, not a probability.

NVD base score

8.4 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-05-12 16:58Z3 MO AGO

Last updated

2026-08-10 15:12Z24 DAYS AGO

Reserved

2026-04-11

Assigning CNA

microsoft

Record state

PUBLISHED

Severity

High (CVSS 8.4)

CNA CVSS vector

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

Weaknesses

• CWE-416Use After FreeVariant

Data version

5.2

Document digest

ff3f8da922379fe75483d513f95f2d4483ecc20c706a8c4d805bab3add77d6e7

• msrc.microsoft.comMicrosoft Word Remote Code Execution Vulnerabilityhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40366vendor-advisorypatch