CVE-2026-55723

{
  "id": "CVE-2026-55723",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-15T15:16:45.327",
  "lastModified": "2026-10-24T21:10:00.130",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "When NGINX Ingress Controller is configured with Custom Resource Definitions (CRDs) or Ingress annotations, an injection vulnerability exists in the configuration generator of NGINX Ingress Controller. Multiple user-controllable fields are written into the generated NGINX configuration without sanitization. An authenticated attacker with permission to create or modify these CRDs or annotations may craft values that inject arbitrary NGINX configuration directives. \n\nImpact:\nAn authenticated attacker granted write access to NGINX Ingress Controller CRDs or Ingress annotations through the Kubernetes API may be able to inject arbitrary NGINX configuration directives, create or delete files, or disable services. There is no data plane exposure; this is a control plane issue only.\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated."
    },
    {
      "lang": "es",
      "value": "Cuando NGINX Ingress Controller está configurado con Definiciones de Recursos Personalizados (CRD) o anotaciones de Ingress, existe una vulnerabilidad de inyección en el generador de configuración de NGINX Ingress Controller. Múltiples campos controlables por el usuario se escriben en la configuración NGINX generada sin saneamiento. Un atacante autenticado con permiso para crear o modificar estas CRD o anotaciones puede elaborar valores que inyecten directivas de configuración NGINX arbitrarias.\n\nImpacto:\nUn atacante autenticado con acceso de escritura concedido a las CRD de NGINX Ingress Controller o a las anotaciones de Ingress a través de la API de Kubernetes podría inyectar directivas de configuración NGINX arbitrarias, crear o eliminar archivos, o deshabilitar servicios. No hay exposición del plano de datos; esto es solo un problema del plano de control.\n\nNota: Las versiones de software que han alcanzado el Fin de Soporte Técnico (EoTS) no se evalúan."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "F5",
          "product": "NGINX Ingress Controller",
          "defaultStatus": "unknown",
          "modules": [
            "Custom Resource Definitions",
            "Ingress Annotations"
          ],
          "versions": [
            {
              "version": "5.0.0",
              "lessThan": "5.5.2",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "2026-lts-r1",
              "lessThan": "2026-lts-r3",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "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:L/SC:N/SI:N/SA:N/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": 8.7,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnAvailabilityImpact": "LOW",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "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": [
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        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
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          "attackVector": "NETWORK",
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          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.5
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-15T00:00:00+00:00",
          "id": "CVE-2026-55723",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-76"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
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  ],
  "references": [
    {
      "url": "https://my.f5.com/manage/s/article/K000161800",
      "source": "[email protected]",
      "tags": [
        "Mitigation",
        "Vendor Advisory"
      ]
    }
  ]
}