CVE-2026-55052: Microsoft SharePoint privilege escalation via missing authorization

CVE-2026-55052 · Severity: high · CVSS 8.8 · Published 2026-07-14

Microsoft SharePoint is a widely used collaboration and document management platform for businesses. A security flaw in the system's authorization checks allows an existing user with low-level access to gain higher-level administrative privileges. This could lead to unauthorized access to sensitive corporate data, modification of site content, or a total loss of control over the SharePoint environment.

Technologies: Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, Microsoft SharePoint Server Subscription Edition. Vendors: Microsoft.

Quick answers

Is CVE-2026-55052 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-55052 being exploited in the wild.
How severe is CVE-2026-55052?
High severity, with a CVSS score of 8.8, published 14 July 2026.
Which products and versions are affected?
Microsoft SharePoint Enterprise Server 2016 < 16.0.5561.1001; Microsoft SharePoint Server 2019 < 16.0.10417.20175; Microsoft SharePoint Server Subscription Edition < 16.0.19725.20434.
Is there a fix for CVE-2026-55052?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-55052 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-55052?
Check whether you run Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019 or Microsoft SharePoint Server Subscription Edition at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A privilege escalation vulnerability exists in Microsoft SharePoint Server due to missing authorization checks (CWE-862). An attacker must be authenticated to the target environment with at least low-privileged user permissions to exploit this flaw. By sending specially crafted network requests to a vulnerable SharePoint instance, the attacker can bypass intended access controls to gain elevated permissions. Successful exploitation grants the attacker high-impact access to confidentiality, integrity, and availability of the server. Affected versions include SharePoint Enterprise Server 2016, SharePoint Server 2019, and SharePoint Server Subscription Edition.

Affected products

  • Microsoft SharePoint Enterprise Server 2016 < 16.0.5561.1001
  • Microsoft SharePoint Server 2019 < 16.0.10417.20175
  • Microsoft SharePoint Server Subscription Edition < 16.0.19725.20434

Timeline

  • 2026-07-14: disclosed
  • 2026-07-14: advisory

References

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