CVE-2026-20963 (GCVE-0-2026-20963)

Vulnerability from cvelistv5 – Published: 2026-01-13 17:56 – Updated: 2026-07-30 20:47
VLAI CISA ENISA Previdian
Title
Microsoft SharePoint Remote Code Execution Vulnerability
Summary
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
SSVC
Exploitation: active Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-01-08 00:00 UTC
CWE
  • CWE-502 - Deserialization of Untrusted Data
Assigner
References
Impacted products
Date Public
2026-01-13 16:00
CISA
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 81974b01-c116-48e8-95da-350ff2abd875

Vulnerability ID: CVE-2026-20963

Status: Confirmed

Status Updated: 2026-03-18 01:00 CET

Exploited: Yes

Timestamps
First Seen: 2026-03-18
Asserted: 2026-03-18
Scope
Notes: Microsoft SharePoint Deserialization of Untrusted Data Vulnerability | Affected: Microsoft / SharePoint | Description: Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network. | Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. | Due date: 2026-03-21 | Known ransomware campaign use (KEV): Unknown | Notes (KEV): https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20963 ; https://nvd.nist.gov/vuln/detail/CVE-2026-20963
Evidence

Type: Vendor Report

Signal: Successful Exploitation

Confidence: 80%

Source: cisa-kev

Details
Cwes CWE-502
Feed CISA Known Exploited Vulnerabilities Catalog
Product SharePoint
Due Date 2026-03-21
Date Added 2026-03-18
Vendorproject Microsoft
Vulnerabilityname Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
Knownransomwarecampaignuse Unknown
References
Created: 2026-10-02 08:09 CEST | Updated: 2026-10-02 08:09 CEST
ENISA
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 2518d78e-983b-45d0-bd52-e3e3a22f3283

Vulnerability ID: CVE-2026-20963

Status: Confirmed

Status Updated: 2026-03-12 01:00 CET

Exploited: Yes

Timestamps
First Seen: 2026-03-12
Asserted: 2026-03-12
Scope
Notes: Affected: Microsoft / Microsoft SharePoint | Description: Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network. | Patched since: 2026/02/13 | Exploitation type: unknown | CWEs: CWE-502 | Origin source: CNW | Notes: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20963
Evidence

Type: Csirt Report

Signal: Successful Exploitation

Confidence: 75%

Source: enisa-cnw-kev

Details
Cwes CWE-502
Euvd EUVD-2026-2114
Notes https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20963
Catalog ENISA / EU CSIRTs Network (CNW) KEV JSON
Product Microsoft SharePoint
Datereported 2026/03/12
Originsource CNW
Patchedsince 2026/02/13
Vendorproject Microsoft
Exploitationtype unknown
Vulnerabilityname
Threatactorsexploiting
References
Created: 2026-10-02 08:52 CEST | Updated: 2026-10-02 08:52 CEST
Previdian
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 068cff49-2209-48b3-a227-a5c33db51fc9

Vulnerability ID: CVE-2026-20963

Status: Confirmed

Status Updated: 2026-06-01 14:10 CEST

Exploited: Yes

Timestamps
First Seen: 2026-06-01
Asserted: 2026-06-01
Scope
Notes: Microsoft SharePoint Remote Code Execution Vulnerability | Affected: Microsoft / Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, Microsoft SharePoint Server Subscription Edition | CVSS: 9.8 (CRITICAL) | EPSS: 0.29582 | Used in malware: unknown | Listed 1 day ahead of CISA KEV | Not yet in CISA KEV: False
Evidence

Type: Public Report

Signal: Successful Exploitation

Confidence: 70%

Source: previdian

Details
Feed Previdian (previdian.com)
Title Microsoft SharePoint Remote Code Execution Vulnerability
Cve Id CVE-2026-20963
Vendor Microsoft
Ghsa Id GHSA-5VR8-9CF6-R7PX
Product Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, Microsoft SharePoint Server Subscription Edition
Added Date 2026-06-01T12:10:26.788Z
Cvss Score 9.8
Epss Score 0.29582
Previous Ids
Cvss Severity CRITICAL
Virtual Patch False
Cvss Estimated False
Epss Percentile 0.98139
Used In Malware unknown
Vulnerability Id CVE-2026-20963
Ahead Of Cisa Kev 
{
  "count": 1,
  "unit": "day"
}
Not Yet In Cisa Kev False
References
Created: 2026-10-02 09:09 CEST | Updated: 2026-10-02 09:09 CEST
Show details on NVD website
To clipboard 

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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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