CVE-2026-40421

🔶 medium

Files or directories accessible to external parties in Microsoft Office Word allows an unauthorized attacker to disclose information locally.

CVSS Score

4.3

Medium

EPSS Score

0.1

Exploit Probability

Published Date

2026-05-12

First Seen: 2026-05-17

This CVE is Lower Risk - more severe than 5.4% of all 326,604 vulnerabilities in our database.

#308,897

Below average severity

Severity Percentile

🔍 Exploitation Status

None

No known exploits

⚙️ Automatable

Requires human interaction

💥 Technical Impact

Partial

Limited system impact

SSVC data provided by CISA

Last Modified 2026-06-01

Source NVD 🔗

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

CWE IDs (Weakness Types)

CWE-73

📦 Affected Products 6

Vendor	Product	Status	Affected Versions
microsoft	office	Affected	v2019
microsoft	office	Affected	v2021
microsoft	office	Affected	v2024
microsoft	word	Affected	v2016
microsoft	365_apps	Affected	v-
microsoft	office_long_term_servicing_channel	Affected	v2021

Vendor Advisory

CVE ID	Severity	CVSS	EPSS	Summary	Published
CVE-2026-42831	⚠️ high	7.8	0.1	Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.	2026-05-12
CVE-2026-42832	⚠️ high	7.7	0.1	Improper access control in Microsoft Office allows an unauthorized attacker to perform spoofing locally.	2026-05-12
CVE-2026-35436	⚠️ high	8.8	0.1	Use after free in Microsoft Office allows an authorized attacker to elevate privileges locally.	2026-05-12
CVE-2026-35440	🔶 medium	5.5	0.0	Files or directories accessible to external parties in Microsoft Office Word allows an unauthorized attacker to disclose...	2026-05-12
CVE-2026-40358	⚠️ high	8.4	0.1	Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.	2026-05-12
CVE-2026-40359	⚠️ high	7.8	0.1	Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code locally.	2026-05-12

These CVEs affect the same products