Patch Actively Exploited Flaws in SharePoint and Winsock
NEOSEC enrichment — no mirror of the original source
Three Microsoft flaws are under recent active exploitation. CVE-2026-55040, CVSS score 9.1, allows an unauthorized attacker to bypass a security feature over a network due to weak authentication in SharePoint. This vulnerability was patched
Source: SANS NewsBites. For licensing reasons NEOSEC Intel does not mirror the full text verbatim. The full text and expert commentary are available at the original source.
Editorial context in the original issue
The SANS NewsBites issue carries commentary by: Dukes, Neely, Skoudis.
Linked advisories
- CVE-2026-55040Microsoft SharePoint Server Security Feature Bypass Vulnerability
- CVE-2026-45659Security Advisory 2026-009 — Critical Vulnerabilities in Microsoft SharePoint
- CVE-2026-45659Microsoft SharePoint Enterprise Server 2016: Deserialisierung nicht vertrauenswürdiger Daten
- CVE-2026-45659Microsoft SharePoint Server — Microsoft SharePoint Server Deserialization of Untrusted Data Vulnerability
- CVE-2026-68820Microsoft Windows Ancillary Function Driver for WinSock — Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability
- CVE-2026-45659Microsoft SharePoint Server 2016 und SharePoint Server 2019: Schwachstelle ermöglicht Codeausführung
- CVE-2026-68820microsoft windows_10_1607: Use-After-Free
- CVE-2026-55040Microsoft SharePoint Enterprise Server 2016: Umgehung einer Sicherheitsfunktion
- CVE-2026-68820Microsoft Windows Produkte: Mehrere Schwachstellen
- CVE-2026-55040Microsoft Office Produkte: Mehrere Schwachstellen
- CVE-2026-45659Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
- CVE-2026-45659Microsoft SharePoint Remote Code Execution Vulnerability
- CVE-2026-68820Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
- CVE-2026-55040Microsoft SharePoint — Microsoft SharePoint Weak Authentication Vulnerability
Affected vendors and products
- Microsoft Microsoft Sharepoint Enterprise Server 2016
- Microsoft Microsoft Sharepoint Server 2019
- Microsoft Microsoft Sharepoint Server Subscription Edition
- Microsoft Microsoft SharePoint Server Subscription Edition
- Microsoft Sharepoint Server 2019
- Microsoft Microsoft Windows 10 1607
- Microsoft Microsoft Windows 10 1809
- Microsoft Microsoft Windows 10 21H2
- Microsoft Microsoft Windows 10 22h2
- Microsoft Windows 10 Version 1607
- Microsoft Windows 10 Version 1809
- Microsoft Windows 10 Version 21h2
More on SharePoint
Other advisories
- Not ratedosv:CLEANSTART-2025-FI55588LibreOffice supports Office URI Schemes to enable browser integration of LibreOffice with MS SharePoint server
- HighCVE-2026-119682An improper access control vulnerability exists in the multi-factor authentication (MFA) functionality of ManageEngine SharePoint Manager Plus (SPMP). A low-…
- HighCVE-2026-119680A stored cross-site scripting (XSS) vulnerability exists in the chart feature of SharePoint Manager Plus (SPMP) due to improper sanitization and HTML encodin…
- HighCVE-2026-119682ManageEngine SharePoint Manager Plus: fehlende Autorisierung
- HighCVE-2026-119682ManageEngine SharePoint Manager Plus: fehlende Autorisierung
- Not ratedosv:CVE-2026-118641n8n before 1.123.85, 2.43.5, and 2.44.1 OData $filter Injection via Outlook and SharePoint Nodes
- HighCVE-2026-108452Microsoft SharePoint Server Subscription Edition: Pfadüberschreitung (Path Traversal)
- HighCVE-2026-108452Eine unzureichende Einschränkung eines Pfadnamens auf ein eingeschränktes Verzeichnis (Pfad-Traversierung) in Microsoft Office SharePoint er...
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- Warlock Expands SharePoint Exploitation in Critical Infrastructure AttacksNewsSecurityWeek
- Microsoft SharePoint Flaw CVE-2026-65660 Now Exploited in AttacksNewsSecurityWeek
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