Description

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an authorized attacker to perform spoofing over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.6",
  "pubDate": "2026-08-11T17:18:53.583Z",
  "pubdate": "2026-08-11T17:18:53.583Z",
  "executiveSummary": "A cross-site scripting (XSS) vulnerability exists within Microsoft Office SharePoint, stemming from the improper neutralization of user-supplied input during web page generation. This security flaw enables an authorized threat actor to execute arbitrary scripts in the context of a victim's browser session over a network.\nThe primary impact of this vulnerability is spoofing, which compromises the integrity and confidentiality of web applications hosted on the affected SharePoint platform. An attacker can leverage this capability to manipulate page content, harvest sensitive session tokens, or masquerade as legitimate users.\nExploitation requires the attacker to possess prior authorization and network access to the vulnerable Microsoft Office SharePoint instance. The attack relies on injecting malicious payloads that are subsequently rendered unsanitized by the web application component, leading to arbitrary script execution within the Document Object Model (DOM) of interacting users.\nOrganizations utilizing Microsoft Office SharePoint face significant risk implications, as successful exploitation undermines trust in enterprise collaboration portals and can serve as an initial vector for broader network compromise or credential theft. Remediation requires applying official vendor patches and enforcing stringent input validation and output encoding mechanisms.",
  "technicalDetails": "The vulnerability is rooted in the failure of Microsoft Office SharePoint to adequately sanitize, validate, or encode user-supplied input before reflecting it within dynamically generated web pages. Specifically, the vulnerable component processes incoming HTTP parameters or data fields without enforcing context-aware output encoding, allowing malicious script tags or event handlers to be embedded directly into the application response.\nBecause the application fails to neutralize input properly, an authorized attacker can construct a crafted URL or submit malicious input payloads containing JavaScript, VBScript, or other executable web vectors. When a target user interacts with the compromised web page or navigates to the malicious link, the browser parses and executes the injected script within the security context of the victim's authenticated session.\nThe attack flow proceeds as follows: First, the attacker establishes network connectivity to the Microsoft Office SharePoint target and authenticates using valid credentials, satisfying the initial privilege requirements. Second, the attacker injects the malicious payload via vulnerable input fields or URL parameters processed by the web application. Third, the application stores or reflects the unsanitized input within the generated HTML output. Fourth, the victim's browser renders the response, executing the injected script under the victim's session.\nPost-exploitation impact includes the potential for session hijacking via access to document.cookie, unauthorized data exfiltration, DOM manipulation leading to spoofing attacks, and the execution of arbitrary actions on behalf of the victimized user within the SharePoint environment. Network exposure is inherent to any deployment accessible via standard web protocols (HTTP/HTTPS), requiring network connectivity to the SharePoint web interface."
}