CVE-2026-56164
MEDIUMCISA KEVEPSS 98th pctlDescription
Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:F/RL:O/RC:C
Exploit Intelligence
Very high risk: more likely to be exploited than 98% of all known CVEs.
Microsoft SharePoint Server Missing Authentication for Critical Function Vulnerability
Microsoft SharePoint contains a missing authentication for critical function vulnerability that allows an unauthorized attacker to elevate privileges over a network.
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Remediation due: 2026-07-17
References
Related Vulnerabilities
Other CWE-306 (Missing Authentication for Critical Function) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2025-3248 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
| CVE-2017-10271 | High | 7.5 | 100% | KEV + Ransom | - |
| CVE-2023-42793 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
| CVE-2022-1388 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
| CVE-2023-21839 | High | 7.5 | 100% | KEV | - |
| CVE-2021-37415 | Critical | 9.8 | 100% | KEV | - |
Common questions
How do I fix CVE-2026-56164?
Published advisories record a fix for 3 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.
Is CVE-2026-56164 being actively exploited?
Yes. CVE-2026-56164 is listed in the CISA Known Exploited Vulnerabilities catalog, which means exploitation has been observed in the wild. US federal agencies were required to remediate it by 2026-07-17. Treat it as a priority whatever its CVSS score says.
How severe is CVE-2026-56164?
CVE-2026-56164 has a CVSS v3 base score of 5.3, rated moderate. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-56164 affect?
Published advisories record a fix for Microsoft SharePoint Enterprise Server 2016 (Microsoft), Microsoft SharePoint Server 2019 (Microsoft), Microsoft SharePoint Server Subscription Edition (Microsoft). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-56164
Markdown
[](https://tridentstack.com/cve/CVE-2026-56164)HTML
<a href="https://tridentstack.com/cve/CVE-2026-56164"><img src="https://tridentstack.com/cve/badge/CVE-2026-56164.svg" alt="CVE-2026-56164"></a>This vulnerability is actively exploited in the wild
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-14.