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CVE-2026-124440

Full vulnerability record from the local CVENow database.

Description

Kyverno from 1.19.1 before 1.19.2 contains an authorization bypass vulnerability in the apiCall namespace clamp that allows namespace tenants to issue cross-namespace and cluster-scoped API requests by appending malformed percent-escapes to urlPath. Attackers can create namespaced Policies whose apiCall runs as the admission-controller ServiceAccount to read other namespaces' resources and create mutating webhooks, escalating to cluster admin.

Severity
CRITICAL
CVSS score
9.4 (v4.0)
Vulnerability status
Received
Source identifier
Published
2026-11-08 14:18:10.633000
Last modified
2026-11-08 14:18:10.633000
View original CVE JSON
{
  "id": "CVE-2026-124440",
  "sourceIdentifier": "[email protected]",
  "published": "2026-11-08T14:18:10.633",
  "lastModified": "2026-11-08T14:18:10.633",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Kyverno from 1.19.1 before 1.19.2 contains an authorization bypass vulnerability in the apiCall namespace clamp that allows namespace tenants to issue cross-namespace and cluster-scoped API requests by appending malformed percent-escapes to urlPath. Attackers can create namespaced Policies whose apiCall runs as the admission-controller ServiceAccount to read other namespaces' resources and create mutating webhooks, escalating to cluster admin."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "kyverno",
          "product": "kyverno",
          "defaultStatus": "unaffected",
          "packageURL": "pkg:golang/github.com/kyverno/kyverno",
          "versions": [
            {
              "version": "1.19.1",
              "lessThan": "1.19.2",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "1.19.2",
              "versionType": "semver",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 9.4,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "HIGH",
          "subIntegrityImpact": "HIGH",
          "subAvailabilityImpact": "HIGH",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "baseScore": 9.9,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "CHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.1,
        "impactScore": 6.0
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-441"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/kyverno/kyverno/security/advisories/GHSA-39w8-hv5g-f73w",
      "source": "[email protected]"
    },
    {
      "url": "https://www.vulncheck.com/advisories/kyverno-1.19.1-privilege-escalation-via-apicall-namespace-clamp-bypass",
      "source": "[email protected]"
    }
  ]
}