Patch tracker / CVE reference / CVE-2026-56164

CVE-2026-56164

CVE-2026-56164 is a medium severity Microsoft vulnerability with a CVSS score of 5.3. It is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it in the wild, which makes it a fix-first item. Microsoft has shipped the fix: deploy one of the 3 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

Risk summary

MediumCISA KEV
5.3
CVSS
77%
EPSS, 30 days
Medium
Severity
Yes
Exploited in the wild

Listed in the CISA Known Exploited Vulnerabilities catalog, confirmed exploited in the wild. EPSS exploit probability 77%. CVSS 5.3 (Medium).

This CVE is among the top 25% of tracked Microsoft CVEs by EPSS exploit probability, and one of 3 actively-exploited CVEs in August 2026.

Senserva Watchevery change we have recorded for this one
What changed, and when

The strongest signal is the CISA KEV listing on 2026-07-14, meaning active exploitation is confirmed. Severity was then raised from 5.3 to 9.8 on 2026-07-23, and EPSS climbed sharply from 0.0% to 21.0% that same day, reaching 57.1% by 2026-07-24. Every indicator is escalating, so prioritize patching today.

0%25%50%75%100%CISA KEVCISA KEV on 2026-07-142026-07-17: EPSS 0.0%2026-07-23: EPSS 21%2026-07-24: EPSS 57%EPSS 57%2026-07-142026-07-24

Drawn by Senserva Vivid from the Senserva change record. Hover any point for its date and value.

  • 2026-07-14 added to the CISA KEV catalog by CISA
  • 2026-07-17 EPSS first scored at 0.0%
  • 2026-07-23 CVSS 5.3 to 9.8; EPSS 0.0% to 21.0%
  • 2026-07-24 EPSS 21.0% to 57.1%

Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.

Senserva AI Opinion for CVE-2026-56164

This SharePoint elevation of privilege flaw is confirmed exploited in the wild by CISA KEV as of 2026-07-14, and its 57 percent EPSS score signals active exploitation attempts against internet-facing servers. Any organization running SharePoint Enterprise Server 2016, SharePoint Server 2019, or the Subscription Edition is exposed, and the Critical rating with CVSS 9.8 means an attacker can gain elevated access on unpatched instances. On-premises SharePoint is a common privilege escalation pivot into wider Active Directory and content compromise.

Do this: Apply Microsoft's SharePoint security update to all affected 2016, 2019, and Subscription Edition servers now, prioritizing any internet-facing farms.

AI-generated from public data, 2026-07-25. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2026-56164

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

Patch now
Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.
Fixed by KB5002882 and 2 more (by build, listed below). Download from the Microsoft Update Catalog, or deploy via Windows Update, Intune, or WSUS.
Do this now: Patch now and verify deployment on every exposed device.

Official patch(es) for CVE-2026-56164

Treat as urgent: it is being exploited in the wild (CISA KEV), so patch ahead of items that are not. In Intune or Defender, confirm whether the fixing updates KB5002882, KB5002883, KB5002891 are installed across the affected products. Senserva does this automatically across your tenant and flags every missing patch.

Apply the Microsoft security updates below to fix CVE-2026-56164. Each KB page carries the Microsoft Update Catalog download, Microsoft's known issues for the update, a copy-paste PowerShell check for whether it is installed, and the Senserva AI read.

Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.

New to a term on this page? CVE, KB, KEV, CVSS, and EPSS are each explained once, on the Senserva security lexicon. Reference: Microsoft CVE and vulnerability management and the Microsoft patching guide.
Provided as is, without warranty; verify against the vendor advisory before acting. Data notice and terms.