Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-56164
“▲” beside the score: it is higher than the CVSS score beside it.
Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-07-14), indicating real-world exploitation has been confirmed by US federal agencies. The CNA's CVSS baseline 5.3 retained for reference (NVD's own analysis pending). Confidence: HIGH.
- Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at low or medium mission impact
A fix is available — apply it.
- CVSS v3
- 5.3
- EG Score
- 9.0CRITICALhigh confidence
- EG Risk
- 96EG Risk 96/100
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computed (value × EchelonGraph’s weight)Severity90% × 45%The EG Score, 9.0 of 10.Exploitation100% × 40%Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Attend at low or medium mission impact; Act at high (mission-essential systems).Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it sooner than your standard update timelines at low or medium mission impact and as soon as possible at high. - EPSS PROB
- 1.0%
- EPSS %ILE
- 62nd
- KEV
- ⚠ Exploited
SSVC (CISA's decision table, applied by EchelonGraph)Attend at low or medium mission impact; Act at high (mission-essential systems).
A fix is available. Apply it sooner than your standard update timelines at low or medium mission impact and as soon as possible at high.
Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 14 days if it is not.
In CISA KEV yes (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
CISA required action“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.”
Quoted verbatim from CISA's Known Exploited Vulnerabilities catalog. CISA directs it at US federal civilian executive branch agencies under Binding Operational Directive (BOD) 26-04, which replaced BOD 22-01 on 10 June 2026; it is not EchelonGraph's advice. CISA's notes: https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-56164 · https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk · https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk · https://nvd.nist.gov/vuln/detail/CVE-2026-56164
Published
July 14, 2026
Last Modified
October 8, 2026
Advisory Details (2)
Auto-updated Oct 13, 2026Security Update Guide - Microsoft Security Response Center
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56164Known Exploited Vulnerabilities Catalog | CISA
Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56164Vendor Advisories for CVE-2026-56164(2)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 80× in last 7d / 417× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 100 of 6,214 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 6,114 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-14 10:58 UTCEG score recompute
- 2026-10-14 10:58 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
- 2026-10-13 09:09 UTCEG score recompute
- 2026-10-13 09:09 UTCVendor advisory
- 2026-10-13 09:09 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
- 2026-10-12 15:55 UTCEG score recompute
- 2026-10-12 07:22 UTCVendor advisory
- 2026-10-12 07:21 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-12 03:27 UTCVendor advisory
- 2026-10-12 03:27 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-11 23:35 UTCVendor advisory
- 2026-10-11 23:34 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-11 19:43 UTCVendor advisory
- 2026-10-11 19:42 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-11 19:38 UTCEG score recompute
- 2026-10-11 16:53 UTCEG score recompute
- 2026-10-11 15:50 UTCVendor advisory
- 2026-10-11 15:50 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-11 14:16 UTCEG score recompute
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
- 2026-10-11 11:59 UTCEG score recompute
- 2026-10-11 11:59 UTCVendor advisory
- 2026-10-11 11:59 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
Show 75 moreShow fewer
- 2026-10-11 08:07 UTCVendor advisory
- 2026-10-11 08:07 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-11 04:16 UTCVendor advisory
- 2026-10-11 04:15 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-11 00:22 UTCVendor advisory
- 2026-10-11 00:22 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-10 20:31 UTCEG score recompute
- 2026-10-10 20:31 UTCVendor advisory
- 2026-10-10 20:31 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
- 2026-10-10 16:39 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-10 12:48 UTCVendor advisory
- 2026-10-10 12:48 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-10 08:55 UTCVendor advisory
- 2026-10-10 08:55 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-10 05:03 UTCVendor advisory
- 2026-10-10 05:03 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-10 01:12 UTCVendor advisory
- 2026-10-10 01:12 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-09 21:19 UTCEG score recompute
- 2026-10-09 21:19 UTCVendor advisory
- 2026-10-09 21:19 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
- 2026-10-09 17:27 UTCVendor advisory
- 2026-10-09 17:27 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-09 13:34 UTCVendor advisory
- 2026-10-09 13:33 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-09 09:43 UTCVendor advisory
- 2026-10-09 09:42 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-09 05:50 UTCVendor advisory
- 2026-10-09 05:49 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-09 01:58 UTCVendor advisory
- 2026-10-09 01:58 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-08 22:07 UTCVendor advisory
- 2026-10-08 22:07 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-08 18:15 UTCEG score recompute
- 2026-10-08 18:15 UTCVendor advisory
- 2026-10-08 18:14 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-08 17:13 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
- 2026-10-08 15:20 UTCVendor advisory
- 2026-10-08 15:20 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-08 11:28 UTCVendor advisory
- 2026-10-08 11:28 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-08 07:37 UTCVendor advisory
- 2026-10-08 07:36 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-08 03:46 UTCVendor advisory
- 2026-10-08 03:45 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-07 23:54 UTCEG score recompute
- 2026-10-07 23:54 UTCVendor advisory
- 2026-10-07 23:54 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
- 2026-10-07 20:03 UTCVendor advisory
- 2026-10-07 20:03 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-07 16:12 UTCVendor advisory
- 2026-10-07 16:11 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-07 12:20 UTCVendor advisory
- 2026-10-07 12:20 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-07 08:29 UTCVendor advisory
- 2026-10-07 08:29 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-07 04:38 UTCVendor advisory
- 2026-10-07 04:38 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-07 00:47 UTCVendor advisory
- 2026-10-07 00:46 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-06 20:55 UTCVendor advisory
- 2026-10-06 20:54 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-06 17:03 UTCEG score recompute
- 2026-10-06 17:03 UTCVendor advisory
- 2026-10-06 17:03 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 1.0% · 61st percentile
- 2026-10-06 13:12 UTCVendor advisory
- 2026-10-06 13:12 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-06 09:20 UTCVendor advisory
- 2026-10-06 09:20 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
- 2026-10-06 05:29 UTCVendor advisory
- 2026-10-06 05:29 UTCGHSA enrichmentGHSA-hc2f-r46j-4w6x · GitHub CVSS 5.3
Publicly available exploits
(2 references)Public exploit code is referenced for this CVE (2 GitHub PoCs). Defenders should treat patch urgency accordingly.
- GitHub PoCsam00/POC-CVE-2026-56164-exploitPublished Aug 6, 2026
CVE-2026-56164 is a critical missing-authentication vulnerability affecting on-premises Microsoft SharePoint Server. It allows unauthenticated, remote attackers to elevate privileges over a network.
Open source ↗ - GitHub PoCsentinel-aidefense/CVE-2026-56164-EXPPublished Jul 15, 2026
CVE-2026-56164 EOP Exploit
Open source ↗
Related CVEs(same CWE)
Frequently asked(6)
What is CVE-2026-56164?
When was CVE-2026-56164 made public?
Is CVE-2026-56164 actively exploited?
What is the CVSS score of CVE-2026-56164?
Which products are affected by CVE-2026-56164?
How do I remediate CVE-2026-56164?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-56164
Is Your Infrastructure Affected by CVE-2026-56164?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.