Is CVE-2026-40366 actively exploited?

No active exploitation of CVE-2026-40366 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-40366 be exploited remotely?

No. CVE-2026-40366 requires local access to exploit.

What is the CVSS score of CVE-2026-40366?

CVE-2026-40366 has a CVSS score of 8.4 (HIGH).

HOME VULNERABILITIESCVE-2026-40366

HIGH

CVE-2026-40366

CWE-416Published: May 12, 2026· Updated: May 13, 2026

8.4

CVSS v3.1

EPSS:0.04%probability of exploitation in 30 daysPercentile:13.6th

Official Description

Use after free in Microsoft Office Word allows an unauthorized attacker to execute code locally.

NVD Source

Technical Analysis

CVE-2026-40366 requires local access, meaning attackers must already have a foothold on the target system.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.4.

From a weakness classification perspective (CWE-416): Use-after-free vulnerabilities involve accessing memory after it has been freed, often enabling arbitrary code execution.