{
  "cveId": "CVE-2026-55040",
  "url": "https://patchblox.com/security/cve/CVE-2026-55040",
  "summary": "CVE-2026-55040 is fixed in 3 products on 1 platform, first by KB5002891, released July 14, 2026. It is being exploited: CISA added it to the Known Exploited Vulnerabilities catalog on August 18, 2026. Patch Radar priority: Patch now.",
  "title": "Microsoft SharePoint Server Security Feature Bypass Vulnerability",
  "description": "\u003Cp\u003EWeak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.\u003C/p\u003E",
  "published": "2026-07-14T07:00:00Z",
  "severity": "Critical",
  "cvss": 9.1,
  "cwe": "Weak Authentication",
  "epss": 0.69536,
  "epssPercentile": 0.99367,
  "priority": "Patch now",
  "priorityTier": 1,
  "exploited": true,
  "vendorExploited": false,
  "disclosed": false,
  "exploitabilityAssessment": "Exploitation More Likely",
  "kev": {
    "added": "2026-08-18T00:00:00Z",
    "due": "2026-08-21T00:00:00Z",
    "ransomware": false,
    "requiredAction": "Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA\u2019s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA\u2019s \u201CForensics Triage Requirements\u201D (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\u0027s internet exposure and ensuring adherence to BOD 26-04 patching guidelines."
  },
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55040",
  "fixes": [
    {
      "platform": "microsoft",
      "product": "Microsoft SharePoint Enterprise Server 2016",
      "fixedVersion": "",
      "fix": "KB5002891",
      "url": "https://patchblox.com/security/fix/microsoft/kb5002891",
      "released": "2026-07-14T07:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Microsoft SharePoint Server 2019",
      "fixedVersion": "",
      "fix": "KB5002883",
      "url": "https://patchblox.com/security/fix/microsoft/kb5002883",
      "released": "2026-07-14T07:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Microsoft SharePoint Server Subscription Edition",
      "fixedVersion": "",
      "fix": "KB5002882",
      "url": "https://patchblox.com/security/fix/microsoft/kb5002882",
      "released": "2026-07-14T07:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}