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.

CISA KEV Check MSRC

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

Explore global source statements, affected packages and advisory history for CVE-2026-45659. The catalog has a separate collection scope from Microsoft release records.

More advisories, affected versions and source history

cve-program · CVE-2026-45659

Published

Microsoft SharePoint Enterprise Server 2016

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "vendor": "Microsoft",
                    "product": "Microsoft SharePoint Enterprise Server 2016",
                    "platforms": [
                        "x64-based Systems"
                    ],
                    "versions": [
                        {
                            "version": "16.0.0",
                            "lessThan": "16.0.5552.1002",
                            "versionType": "custom",
                            "status": "affected"
                        }
                    ]
                }

Microsoft SharePoint Server 2019

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "vendor": "Microsoft",
                    "product": "Microsoft SharePoint Server 2019",
                    "platforms": [
                        "x64-based Systems"
                    ],
                    "versions": [
                        {
                            "version": "16.0.0",
                            "lessThan": "16.0.10417.20128",
                            "versionType": "custom",
                            "status": "affected"
                        }
                    ]
                }

Microsoft SharePoint Server Subscription Edition

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "vendor": "Microsoft",
                    "product": "Microsoft SharePoint Server Subscription Edition",
                    "platforms": [
                        "x64-based Systems"
                    ],
                    "versions": [
                        {
                            "version": "16.0.0",
                            "lessThan": "16.0.19725.20280",
                            "versionType": "custom",
                            "status": "affected"
                        }
                    ]
                }

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