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CVE-2026-56164

MEDIUM 5.3 KNOWN EXPLOITED ALL-YEARS

Published 2026-07-14 · Last modified 2026-10-08 · microsoft · NVD: Analyzed

Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.

ACTIVELY EXPLOITED

Confirmed exploited in the wild — in CISA KEV since 2026-07-14. Patch or mitigate now.

Exploitation likelihood

1.0%chance of exploitation in 30 days · 63rd percentile

● In CISA KEV (2026-07-14)○ Catalogued PoC◆ SSVC: exploitation active, automatable yes

Impact if exploited

5.3CVSS 3.1 · MEDIUM · CNA

  • ConfidentialityNone
  • IntegrityLow
  • AvailabilityNone

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

Search for new PoCs

Search GitHub now — results may be empty or unverified.

Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Affected

Vendors Microsoft

Products Microsoft Sharepoint Enterprise Server 2016 Microsoft Sharepoint Server 2019 Microsoft Sharepoint Server Subscription Edition Sharepoint Server

Weakness (CWE)

  • CWE-306: : Missing Authentication for Critical Function

CVSS vector

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

References and research data (JSON)

Unverified PoC candidates

Catalogue matches for further research. These repositories have not been validated as working exploits.

2 candidates

Additional exploitation reports

Source-specific reports, separate from CISA KEV. Repeated observations from one source are not independent confirmations.

Known Affected Software Configurations

VendorProductVersion range
MicrosoftSharepoint Server< 16.0.19725.20434
MicrosoftSharepoint Server2016
MicrosoftSharepoint Server2019

All CVSS metrics

  • MEDIUM 5.3 v3.1 · CNA Primary
    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
  • MEDIUM 5.3 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
  • CRITICAL 9.8 v3.1 · NVD Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Patches & mitigations

Advisories

Technical & other

Sources: NVD · CVE.org · All sources and attribution · EPSS