CVE-2026-45659CISA KEV

Microsoft SharePoint Server Deserialization of Untrusted Data Vulnerability

Severity unknownCVSS unknownCheck the vendor advisory for fixed versions

CISA lists this Microsoft vulnerability as known exploited. Its MSRC release detail is outside this installation's collected history.

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CISA catalog record

Microsoft SharePoint Server contains a deserialization of untrusted data vulnerability which allows an authorized attacker to execute code over a network.

Product: SharePoint Server
Added to KEV: 1 Jul 2026
Federal remediation due: 4 Jul 2026
Known ransomware use: Yes

Page history

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Field-level log (2)

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23 Oct 2026 · 09:33:49 UTC Source coverage: cisa-kevIncomplete → Current
23 Oct 2026 · 08:31:50 UTC Source coverage: cisa-kevCurrent → Incomplete

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Exploitation and risk

Source status

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CVE-2026-45659

Listed in CISA KEV · added 1 Jul 2026 · Microsoft · SharePoint Server

Microsoft SharePoint Server contains a deserialization of untrusted data vulnerability which allows an authorized attacker to execute code over a network.

CISA source

No EPSS score is available here for this CVE.

Saved 23 Oct 2026 16:01:26 UTC · View this risk record (JSON)

cve-program · CVE-2026-45659

Published

Microsoft SharePoint Remote Code Execution Vulnerability

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

Source published: 22 May 2026 22:04:33 UTC
Source modified: 11 Aug 2026 03:55:31 UTC
Saved here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

CVSS 3.1 · 8.8 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