CVE-2026-58277 Microsoft CVE debrief

Who should care

Defenders responsible for Microsoft SharePoint Enterprise Server 2016 and Microsoft SharePoint Server 2019 deployments should assess exposure and prioritize patching.

Why it matters

CVE-2026-58277 is a high-severity elevation of privilege vulnerability in Microsoft SharePoint that allows an authorized attacker to elevate privileges over a network. Defenders should prioritize verifying and applying patches for Microsoft SharePoint Enterprise Server 2016 and Microsoft SharePoint Server 2019, assessing exposure and implementing compensating controls if necessary.

• Verify and apply patches to prevent privilege elevation
• Assess exposure and implement compensating controls if necessary
• Monitor for suspicious activity related to SharePoint

Technical summary

The vulnerability is caused by improper authorization in Microsoft Office SharePoint, allowing an authorized attacker to elevate privileges over a network. This vulnerability affects Microsoft SharePoint Enterprise Server 2016 and Microsoft SharePoint Server 2019. The vulnerability allows an authorized attacker to elevate privileges over a network due to improper authorization in Microsoft Office SharePoint.

Defensive priority

Defenders should prioritize verifying and applying patches for Microsoft SharePoint Enterprise Server 2016 and Microsoft SharePoint Server 2019, assessing exposure and implementing compensating controls if necessary.

Recommended defensive actions

• Verify and apply patches for Microsoft SharePoint Enterprise Server 2016 and Microsoft SharePoint Server 2019
• Assess exposure and implement compensating controls if necessary
• Monitor for suspicious activity related to SharePoint

Evidence notes

The CVE record and source item provide details on the vulnerability, affected products, and references to vendor advisories. The vulnerability is caused by improper authorization in Microsoft Office SharePoint, allowing an authorized attacker to elevate privileges over a network. There are references to vendor advisories and patch information for CVE-2026-58277. The source item provides details on the vulnerability and affected products. The official CVE Program record and NIST NVD

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.