CVE-2026-55019

Microsoft SharePoint Server Spoofing Vulnerability

Published Jul 14, 2026 CVSS 3.1 · 4.6 Medium EPSS < 1% KEV · Not listed
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.

Analysis

AI-generated

Technical impact

Improper neutralization of user input during web page generation on Microsoft SharePoint leads to a cross‑site scripting flaw that can allow an attacker to inject malicious scripts into pages. The injected code can mimic legitimate site behavior, causing users to be misled or to unknowingly submit sensitive information to the attacker. This classic XSS weakness (CWE‑79) primarily threatens the integrity of page content and the trust users place in the site, potentially enabling social‑engineering attacks rather than direct code execution.

Affected Systems

Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, and Microsoft SharePoint Server Subscription Edition are all affected by this flaw. No specific build or patch level is listed, so all current installations of these products are potentially vulnerable until a patch is applied.

Risk and Exploitability

The CVSS score of 4.6 classifies the issue as medium severity. The EPSS score of less than 1% indicates a low probability of exploitation at this time, and the vulnerability is not listed in the CISA KEV catalog. The likely attack vector is through web content that an authorized user can edit; based on the description, it is inferred that the attacker must first have edit or add‑content permissions to insert malicious scripts, after which other users viewing the crafted page will execute the injected code.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Apply the latest SharePoint security update from Microsoft as documented on the MSRC advisory.
  • Restrict user permissions to limit who can add or modify page content that may be rendered on the site.
  • Validate and escape all user input before including it in page rendering to prevent script injection.

Generated by OpenCVE AI on July 31, 2026 at 07:06 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Microsoft SharePoint Server Spoofing Vulnerability
First Time appeared Microsoft
Microsoft sharepoint Server
Microsoft sharepoint Server 2016
Microsoft sharepoint Server 2019
Weaknesses CWE-79
CPEs cpe:2.3:a:microsoft:sharepoint_server:*:*:*:*:subscription:*:*:*
cpe:2.3:a:microsoft:sharepoint_server_2016:*:*:*:*:enterprise:*:*:*
cpe:2.3:a:microsoft:sharepoint_server_2019:*:*:*:*:*:*:*:*
Vendors & Products Microsoft
Microsoft sharepoint Server
Microsoft sharepoint Server 2016
Microsoft sharepoint Server 2019
References
Metrics cvssV3_1

{'score': 4.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C'}

Weaknesses
  • CWE-79

    Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Sources

Status
PUBLISHED
Assigner
microsoft
Published
Updated
Nov 10, 2026, 10:39 PM
Reserved
Jun 16, 2026, 2:12 PM
Status
Analyzed
Published
Jul 14, 2026, 6:18 PM
Modified
Jul 15, 2026, 3:13 PM