CVE-2026-45645 | Microsoft Office Remote Code Execution Vulnerability

Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.

Published: 2026-06-09 Last update: 2026-06-19 Assigner: [email protected] Source: [email protected]

NVD Status：Analyzed，CVE State: published

View at NVD, CVE.org, EUVD

Threat Intelligence & Risk Assessment for CVE-2026-45645

EPSS CVSS CWE GHSA Affected

Conclusion & alert: CVE-2026-45645 is rated Moderate Risk (41.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.37%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-45645

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-23	0.30%	0.37%	+0.07%
2	2026-06-15	0.08%	0.30%	+0.22%
3	2026-06-10	—	0.08%	—

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-45645

CVSS metrics for this CVE.

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	[email protected]

Weakness enumeration for CVE-2026-45645

CWE-787 MITRE ↗ CWE-822 MITRE ↗

GitHub Security Advisory for CVE-2026-45645

GHSA-wxr3-p34c-5p9q · Severity: high — Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code...

Affected software / configurations for CVE-2026-45645

Vendor	Product	Version	Raw CPE
microsoft	office_365	>= 1.0.0, < 16.110.26061317	cpe:2.3:a:microsoft:office_365::::::macos::*
microsoft	office_2019	>= 19.0.0, < https://aka.ms/OfficeSecurityReleases	cpe:2.3:a:microsoft:office_2019::::::::
microsoft	365_apps	>= 16.0.1, < https://aka.ms/OfficeSecurityReleases	cpe:2.3:a:microsoft:365_apps:::::enterprise:::*
microsoft	office_macos_2021	>= 16.0.1, < 16.110.26061317	cpe:2.3:a:microsoft:office_macos_2021::::::long_term_servicing_channel::*
microsoft	office_2021	>= 16.0.1, < https://aka.ms/OfficeSecurityReleases	cpe:2.3:a:microsoft:office_2021:::::long_term_servicing_channel:::*
microsoft	office_2024	>= 16.0.0, < https://aka.ms/OfficeSecurityReleases	cpe:2.3:a:microsoft:office_2024:::::long_term_servicing_channel:::*
microsoft	office_macos_2024	>= 16.0.0, < 16.110.26061317	cpe:2.3:a:microsoft:office_macos_2024::::::long_term_servicing_channel::*
microsoft	office_2016	>= 16.0.0, < 16.0.5556.1001	cpe:2.3:a:microsoft:office_2016:::::::x86:*

References for CVE-2026-45645

URL	Tags
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45645	Vendor Advisory

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