CVE-2026-56157: Microsoft SharePoint improper access control spoofing vulnerability

CVE-2026-56157 · Severity: medium · CVSS 5.4 · Published 2026-07-14

Microsoft SharePoint, a widely used collaboration and document management platform, contains a security flaw that could allow an authorized user to impersonate other users or services. While the attacker must already have basic access to the network, they could use this vulnerability to misrepresent their identity, potentially leading to unauthorized actions or data access. Organizations should apply the latest security updates from Microsoft to protect their internal communications and data integrity.

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

Quick answers

Is CVE-2026-56157 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-56157 being exploited in the wild.
How severe is CVE-2026-56157?
Medium severity, with a CVSS score of 5.4, published 14 July 2026.
Which products and versions are affected?
Microsoft SharePoint Enterprise Server 2016 16.0.0 to 16.0.5561.1001; Microsoft SharePoint Server 2019 16.0.0 to 16.0.10417.20175; Microsoft SharePoint Server Subscription Edition 16.0.0 to 16.0.19725.20434.
Is there a fix for CVE-2026-56157?
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-2026-56157 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-56157?
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 spoofing vulnerability exists in Microsoft SharePoint due to improper access control (CWE-284). An authenticated attacker with low privileges can exploit this flaw over the network without requiring user interaction. Successful exploitation allows the attacker to spoof identities or communications within the SharePoint environment, potentially compromising data integrity or confidentiality. The vulnerability affects SharePoint Enterprise Server 2016, SharePoint Server 2019, and SharePoint Server Subscription Edition. Microsoft has released security updates to address this issue.

Affected products

  • Microsoft SharePoint Enterprise Server 2016 16.0.0 to 16.0.5561.1001
  • Microsoft SharePoint Server 2019 16.0.0 to 16.0.10417.20175
  • Microsoft SharePoint Server Subscription Edition 16.0.0 to 16.0.19725.20434

Timeline

  • 2026-07-14: advisory: Initial publication by Microsoft and NVD

References

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