HIGH CISA KEV

CVE-2026-45659

CVSS v3

8.8

HIGH

EPSS Score

2.7 %

exploit probability, as of 2026-10-03

CISA KEV

Yes

known exploited

Exploitation

—

SSVC status

Description

Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

CISA Known Exploited Vulnerability

Date Added: 2026-07-01
Patch Due Date: 2026-07-04
Ransomware Use: Unknown

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Published: 2026-05-22
Last Modified: 2026-07-23
MSRC Title: Microsoft SharePoint Remote Code Execution Vulnerability

Frequently asked questions

What is CVE-2026-45659?

Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

Is CVE-2026-45659 actively exploited?

Yes. CVE-2026-45659 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2026-07-04.

What is the CVSS score for CVE-2026-45659?

CVE-2026-45659 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C.

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