CVE-2026-20958

Medium

Published: 13 January 2026

Published

13 January 2026

Modified

14 January 2026

KEV Added

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Patch

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CVSS Score v3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

EPSS Score 0.0008 23.8th percentile

Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-20958 is a medium-severity SSRF (CWE-918) vulnerability in Microsoft Sharepoint Server. Its CVSS base score is 5.4 (Medium).

Operationally, ranked at the 23.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

Server-side request forgery (ssrf) in Microsoft Office SharePoint allows an authorized attacker to disclose information over a network.

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

microsoft

sharepoint server

2016, 2019 · ≤ 16.0.19127.20442

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-918

Penetration testing attempts server-side requests to internal resources, identifying SSRF weaknesses for remediation.

addresses: CWE-918

Outbound connections to external resources can be monitored and limited at the boundary, reducing SSRF impact.

addresses: CWE-918

Validates server-side URLs and resource references to block SSRF attempts.

addresses: CWE-918

Detects server-side request forgery through monitoring of unexpected outbound connections.