CVE-2026-40420

⚠️ high

🔍 Scan for this CVE

Use after free in Microsoft Office allows an authorized attacker to elevate privileges locally.

CVSS Score

8.8

High

EPSS Score

0.1

Exploit Probability

Published Date

2026-05-12

First Seen: 2026-05-20

This CVE is High Risk - more severe than 81.1% of all 327,350 vulnerabilities in our database.

#61,883

Top 25% most severe

Severity Percentile

🔍 Exploitation Status

None

No known exploits

⚙️ Automatable

Requires human interaction

💥 Technical Impact

Total

Complete system compromise possible

SSVC data provided by CISA

Last Modified 2026-06-01

Source NVD 🔗

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

CWE IDs (Weakness Types)

CWE-284

📦 Affected Products 4

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

Vendor Advisory

CVE ID	Severity	CVSS	EPSS	Summary	Published
CVE-2026-44817	⚠️ high	7.8	0.2	Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally...	2026-06-09
CVE-2026-44818	⚠️ high	7.0	0.0	Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally...	2026-06-09
CVE-2026-44819	⚠️ high	7.8	0.1	Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.	2026-06-09
CVE-2026-44820	⚠️ high	7.8	0.1	Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally...	2026-06-09
CVE-2026-44821	🔶 medium	5.5	0.1	Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.	2026-06-09
CVE-2026-44822	⚠️ high	8.2	0.1	Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network.	2026-06-09

These CVEs affect the same products