【Vulnerability Alert】Microsoft SharePoint Server Has a Critical Information Security Vulnerability (CVE-2026-45659)

publish date : 2026-05-29 update date : 2026-05-29

Source: Ministry of education information & communication security contingency platform

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Publication Number TACERT-ANA-2026052804051212 Publication Time 2026-05-28 16:05:14
Incident Type ANA-Vulnerability Alert Discovery Time 2026-05-28 16:05:14
Impact Level Low  
[Subject]
【Vulnerability Alert】Microsoft SharePoint Server Has a Critical Information Security Vulnerability (CVE-2026-45659)
[Content]

Forwarded from TWCERTCC Security Advisory TWCERTCC-200-202605-00000015

Microsoft SharePoint Server is an enterprise-level collaboration platform that provides functions such as document management and team collaboration,
and is a core platform for enterprise information integration.
Recently, Microsoft released a critical security advisory (CVE-2026-45659, CVSS: 8.8).
This vulnerability is a deserialization of untrusted data vulnerability,
which allows an authenticated attacker to execute code over the network.

Information Sharing Level: WHITE
(the intelligence content is information that may be publicly disclosed)
[Affected Platform]

Microsoft SharePoint Enterprise Server 2016 versions earlier than 16.0.5552.1002, not inclusive,

Microsoft SharePoint Server 2019 versions earlier than 16.0.10417.20128, not inclusive,

Microsoft SharePoint Server Subscription Edition versions earlier than 16.0.19725.20280, not inclusive
[Recommended Actions]

Apply patches according to the solution released on the official website:

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45659

[Reference]
(This notification is for informational purposes only and does not constitute a cybersecurity incident).
If you have questions or suggestions regarding this notification, please feel free to contact us.
Ministry of education information & communication security contingency platform
Website: https://info.cert.tanet.edu.tw/
Phone: +886-7-5250211
Internet Phone: 98400000
E-Mail: service@cert.tanet.edu.tw
Organizer: Computer Center