CVE-2026-56164

Microsoft SharePoint Server: Missing Authentication for Critical Function

As of , CVE-2026-56164 in Microsoft SharePoint Server is on CISA's list of exploited vulnerabilities: CISA listed it on . Our patch-first group: Patch now.

Exploited
Yes: CISA listed it on 14 July 2026
US federal deadline
17 July 20263 days after CISA listed it. US federal civilian agencies must fix it by then.
Used in ransomware campaigns
Not known to CISA
Forensic triage
Required by CISA under BOD 26-04Agencies must also look for signs that attackers already got in.
EPSS score
0.01Higher than 61% of the CVEs EPSS scores. EPSS estimates the chance of exploitation activity in the next 30 days.
Public exploit
None foundNeither Metasploit nor Exploit-DB lists one.
Fix
Vendor advice: msrc.microsoft.comLinks below, from CISA's entry.

What CISA says to do

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

CISA's required action

What the flaw is

Microsoft SharePoint contains a missing authentication for critical function vulnerability that allows an unauthorized attacker to elevate privileges over a network.

CISA's description

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

The CVE record's description, from microsoft

CVE published
14 July 2026
Assigned by
microsoft
CVSS
5.3 Medium (CVSS 3.1, from the CNA)
CWE-306
Missing Authentication for Critical Function
CISA SSVC, exploitation
active
CISA SSVC, automatable
yes
CISA SSVC, technical impact
partial

Timeline

  1. The CVE record was published.
  2. CISA added it to its list of exploited vulnerabilities.
  3. The US federal deadline to fix it.

SharePoint Server: other exploited entries

VulnerabilityProductOur groupListedDeadlineEPSS
CVE-2026-45659Deserialization of Untrusted DataMicrosoft SharePoint ServerPatch nowForensic triage required by CISA; ransomware use, listed within a year0.03
CVE-2023-24955Code InjectionMicrosoft SharePoint ServerPatch this weekRansomware use; Metasploit module; EPSS 0.850.85
CVE-2023-29357Privilege EscalationMicrosoft SharePoint ServerPatch this weekRansomware use; Metasploit module; EPSS 0.990.99
CVE-2026-32201Improper Input ValidationMicrosoft SharePoint ServerPatch soon0.43

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