This vulnerability (CVE-2026-47639) affects Microsoft SharePoint Enterprise Server 2016 (version 16.0.0). It is classified as CWE-79, indicating improper neutralization of input during web page generation, leading to cross-site scripting (XSS). An authorized attacker can exploit this flaw to perform spoofing attacks over a network. The CVSS 3.1 base score is 5.4 (medium severity), with network attack vector, low attack complexity, no privileges required, user interaction required, and impacts on confidentiality and integrity. Microsoft has released an official fix for this vulnerability as documented in their security update guide.

Exploitation of this vulnerability could allow an authorized attacker to conduct spoofing attacks by injecting malicious scripts into web pages generated by SharePoint. This may lead to limited confidentiality and integrity impacts, such as unauthorized disclosure or modification of information within the context of the affected SharePoint environment. There is no indication of availability impact or known exploits in the wild at this time.

An official fix is available from Microsoft for this vulnerability. It is recommended to apply the security update provided by Microsoft as detailed in their advisory (https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47639). Since this is not a cloud service, remediation requires patching the affected SharePoint Enterprise Server 2016 installations. No additional mitigation steps are specified by the vendor.