Microsoft SharePoint Enterprise Server deserialization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.4$0-$5k0.00

Summaryinfo

A vulnerability described as critical has been identified in Microsoft SharePoint Enterprise Server. Affected by this issue is some unknown functionality. Such manipulation leads to deserialization. This vulnerability is referenced as CVE-2026-45659. It is possible to launch the attack remotely. Furthermore, an exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Microsoft SharePoint Enterprise Server (unknown version). It has been rated as critical. Affected by this issue is an unknown code block. The manipulation with an unknown input leads to a deserialization vulnerability. Using CWE to declare the problem leads to CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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

The advisory is shared for download at msrc.microsoft.com. This vulnerability is handled as CVE-2026-45659 since 05/12/2026. The exploitation is known to be easy. The attack may be launched remotely. Technical details are unknown but an exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 07/02/2026).

It is declared as attacked. This issue was added on 07/01/2026 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 07/04/2026:

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BO

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at EUVD (EUVD-2026-31518) and CERT Bund (WID-SEC-2026-1652). Once again VulDB remains the best source for vulnerability data.

Affected

  • Microsoft SharePoint Server 2016
  • Microsoft SharePoint Server 2019
  • Microsoft SharePoint

Productinfo

Type

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.6
VulDB Meta Temp Score: 7.4

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.8
CNA Vector (microsoft): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Deserialization
CWE: CWE-502 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Attacked

EPSS Score: 🔒
EPSS Percentile: 🔒

KEV Added: 🔒
KEV Due: 🔒
KEV Remediation: 🔒
KEV Ransomware: 🔒
KEV Notice: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

05/12/2026 CVE reserved
05/23/2026 +11 days Advisory disclosed
05/23/2026 +0 days VulDB entry created
07/02/2026 +39 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-45659 (🔒)
GCVE (CVE): GCVE-0-2026-45659
GCVE (VulDB): GCVE-100-365300
EUVD: 🔒
CERT Bund: WID-SEC-2026-1652 - Microsoft SharePoint Server 2016 und SharePoint Server 2019: Schwachstelle ermöglicht Codeausführung

scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 05/23/2026 07:58
Updated: 07/02/2026 01:54
Changes: 05/23/2026 07:58 (61), 05/23/2026 16:51 (7), 05/24/2026 02:53 (1), 07/02/2026 01:54 (12)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

Discussion

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