Summary
Impact: Information Disclosure. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.
Details
What type of information could be disclosed through this issue?
The vulnerability may allow limited exposure of data returned from outbound requests SharePoint makes on the attacker’s behalf, such as external HTTP responses or basic network metadata, but not internal network content or sensitive server information.
According to the CVSS metrics, successful exploitation of this vulnerability could lead to some loss of confidentiality (C:L), and integrity (I:L) but lead to no loss of availability (A:N). What is the impact of this vulnerability?
An attacker who successfully exploited the vulnerability could view some sensitive information (Confidentiality), make changes to disclosed information (Integrity), but cannot limit access to the resource (Availability).
Security updates
16.0.5535.1001 — https://support.microsoft.com/help/5002828
16.0.10417.20083 — https://support.microsoft.com/help/5002825
16.0.19127.20442 — https://support.microsoft.com/help/5002822
Vulnerabilities 1
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Medium 5.4
Microsoft SharePoint Information Disclosure Vulnerability
Server-side request forgery (ssrf) in Microsoft Office SharePoint allows an authorized attacker to disclose information over a network.
Revision history
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#2
Updated acknowledgment. This is an informational change only.
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#1
Information published.
References
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CVE-2026-20958 Microsoft SharePoint Information Disclosure Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20958
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Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
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Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
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Common Vulnerability Scoring System
https://www.first.org/cvss