CVE-2026-20951

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{}

{"analysis": {"en": {"generated_at": "2026-04-16T18:15:13.862635+00:00", "value": {"mitigation_remediation": ["Install the security update for Microsoft SharePoint Server 2016, 2019, and Subscription Edition that addresses the input validation flaw, as described in the Microsoft Security Update Guide.", "Block external access to SharePoint Server services from untrusted networks using firewall rules or a reverse proxy to reduce the attack surface.", "Enable detailed audit logging for SharePoint and review logs regularly to detect any anomalous activity after the update."], "summary": {"action": "Immediate Patch", "impact": "Remote Code Execution"}, "threat_synthesis": {"affected_systems": "Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, and Microsoft SharePoint Server Subscription Edition are compromised when running unpatched versions. The vulnerability applies to all product releases identified by the Microsoft CNA that are listed in the known affected products.", "description_and_impact": "The vulnerability is an improper input validation flaw that permits an attacker without authorization to execute arbitrary code locally on Microsoft SharePoint Server installations. The flaw could allow the execution of malicious scripts or binaries with the privileges of the SharePoint service process, potentially compromising the integrity and confidentiality of the affected system and the data stored within it.", "risk_and_exploitability": "The CVSS score of 7.8 indicates high severity, while the EPSS score of less than 1% shows a very low probability of exploitation at the time of reporting. The vulnerability is not currently featured in the CISA KEV catalog. The attack vector is inferred to be remote, typically via malicious input sent over the network to SharePoint processes, because the flaw involves input validation in a web\u2011based component. A successful exploit would grant code execution rights to the attacker with the same privileges as the SharePoint service account."}}}}, "created": "2026-04-16T18:15:43.302118+00:00", "updated": "2026-04-16T18:15:43.302128+00:00", "vendors": []}