{"cve":{"cve_id":"CVE-2026-20963","is_kev":true,"kev_date_added":"2026-03-18","kev_vendor_project":"Microsoft","kev_product":"SharePoint","kev_vulnerability_name":"Microsoft SharePoint Deserialization of Untrusted Data Vulnerability","kev_short_description":"Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.","kev_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.","kev_due_date":"2026-03-21","kev_known_ransomware":false,"kev_notes":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20963 ; https://nvd.nist.gov/vuln/detail/CVE-2026-20963","kev_cwes":["CWE-502"],"epss_score":0.31109,"epss_percentile":0.98032,"epss_as_of":"2026-06-23","description":"Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.","published_at":"2026-01-13T17:56:49.798000Z","last_modified_at":null,"cvss_v3_score":9.8,"cvss_v3_vector":"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","cvss_v3_severity":"CRITICAL","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-502"],"nvd_references":["https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20963"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:31.350578Z","updated_at":"2026-06-28T23:29:04.784299Z"},"effective_severity":"CRITICAL","badges":["kev"],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"H","value_label":"High"},{"metric":"A","name":"Availability","value":"H","value_label":"High"},{"metric":"E","name":"E","value":"U","value_label":"Unchanged"},{"metric":"RL","name":"RL","value":"O","value_label":"O"},{"metric":"RC","name":"RC","value":"C","value_label":"Changed"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"microsoft","vendor_name":"Microsoft","product_slug":"microsoft-sharepoint-enterprise-server-2016","product_name":"Microsoft SharePoint Enterprise Server 2016","version_start":"16.0.0","version_start_inclusive":true,"version_end":"16.0.5535.1001","version_end_inclusive":false,"cpe23_uri":"cve5:microsoft:microsoft-sharepoint-enterprise-server-2016:16.0.0:16.0.5535.1001"},{"vendor_slug":"microsoft","vendor_name":"Microsoft","product_slug":"microsoft-sharepoint-server-2019","product_name":"Microsoft SharePoint Server 2019","version_start":"16.0.0","version_start_inclusive":true,"version_end":"16.0.10417.20083","version_end_inclusive":false,"cpe23_uri":"cve5:microsoft:microsoft-sharepoint-server-2019:16.0.0:16.0.10417.20083"},{"vendor_slug":"microsoft","vendor_name":"Microsoft","product_slug":"microsoft-sharepoint-server-subscription-edition","product_name":"Microsoft SharePoint Server Subscription Edition","version_start":"16.0.0","version_start_inclusive":true,"version_end":"16.0.19127.20442","version_end_inclusive":false,"cpe23_uri":"cve5:microsoft:microsoft-sharepoint-server-subscription-edition:16.0.0:16.0.19127.20442"}],"exploit_refs":[],"news":[],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20963","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2026-01-13T17:56:49.798000Z","label":"CVE published","source":null},{"type":"cisa_reported","at":"2026-03-18T00:00:00Z","label":"Added to CISA KEV catalog","source":"kev"},{"type":"cvss_changed","at":"2026-06-28T17:51:25.596901Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:51:25.596901Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:51:25.596901Z","label":"CVSS score revised","source":"cvelistv5"}]}