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

Vulnerability from cvelistv5 – Published: 2026-01-13 17:56 – Updated: 2026-04-02 03:55
VLAI CISA KEV EUVD KEV KEVintel KEV
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 (v2.0.3)
CWE
  • CWE-502 - Deserialization of Untrusted Data
Assigner
References
Impacted products
Date Public
2026-01-13 16:00
CISA KEV
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 89e95885-1490-4942-a08d-70a2423ae944

Vulnerability ID: CVE-2026-20963

Status: Confirmed

Status Updated: 2026-03-18 00:00 UTC

Exploited: Yes

Timestamps
First Seen: 2026-03-18
Asserted: 2026-03-18
Scope
Notes: KEV entry: 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: 2026-03-18 21:00 UTC | Updated: 2026-03-18 21:00 UTC
EUVD KEV
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 3ee8b94d-e3a5-4b6b-af02-e4b82bc805c0

Vulnerability ID: CVE-2026-20963

Status: Confirmed

Status Updated: 2026-03-12 00:00 UTC

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. | 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
Vendorproject Microsoft
Exploitationtype -
Vulnerabilityname -
Threatactorsexploiting -
References
Created: 2026-05-21 09:12 UTC | Updated: 2026-05-21 09:12 UTC
KEVintel KEV
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 22fa7703-4d66-48a8-88d8-5270f6a5086a

Vulnerability ID: CVE-2026-20963

Status: Confirmed

Status Updated: 2026-06-01 12:10 UTC

Exploited: Yes

Timestamps
First Seen: 2026-06-01
Asserted: 2026-06-01
Scope
Notes: KEVIntel entry: 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: 0.31109 | Used in malware: unknown | Not yet in CISA KEV: False
Evidence

Type: Public Report

Signal: Successful Exploitation

Confidence: 70%

Source: kevintel

Details
Feed KEVIntel (kevintel.com)
Title Microsoft SharePoint Remote Code Execution Vulnerability
Vendor Microsoft
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 0.31109
Cvss Severity CRITICAL
Epss Percentile 0.98038
Used In Malware unknown
Ahead Of Cisa Kev 
{
  "count": 1,
  "unit": "day"
}
Not Yet In Cisa Kev False
References
Created: 2026-06-19 12:45 UTC | Updated: 2026-06-19 12:45 UTC
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.