CVE-2026-62143

Full vulnerability record from the local CVENow database.

Description

A Server-Side Request Forgery (SSRF) protection bypass existed in the html_to_markdown expansion module of misp-modules. The module attempts to prevent requests to loopback, private, link-local, and other restricted IP address ranges. However, IP addresses were compared against the blocked ranges without first normalising IPv4-mapped IPv6 addresses. An authenticated attacker able to invoke the module could supply an IPv4-mapped IPv6 address, such as: http://[::ffff:127.0.0.1]/ http://[::ffff:169.254.169.254]/ Alternatively, the attacker could use a hostname that resolves to an IPv4-mapped IPv6 address. These addresses were treated as IPv6 addresses and therefore did not match the corresponding blocked IPv4 ranges. Successful exploitation could cause the misp-modules server to connect to services available through its loopback interface, internal network, or link-local network. This could expose internal web services, administrative interfaces, or cloud instance metadata, with retrieved content potentially returned to the attacker as converted Markdown. The vulnerability has been addressed by normalising IPv4-mapped IPv6 addresses to their underlying IPv4 representation before applying the blocked-range checks. URLs without a valid hostname are now also rejected.

Severity

HIGH

CVSS score

8.3 (v4.0)

Vulnerability status

Deferred

Source identifier

5a6e4751-2f3f-4070-9419-94fb35b644e8

Published

2026-07-13 09:16:24.700000

Last modified

2026-10-24 22:10:00.210000

View original CVE JSON

{
  "id": "CVE-2026-62143",
  "sourceIdentifier": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
  "published": "2026-07-13T09:16:24.700",
  "lastModified": "2026-10-24T22:10:00.210",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A Server-Side Request Forgery (SSRF) protection bypass existed in the html_to_markdown expansion module of misp-modules.\n\nThe module attempts to prevent requests to loopback, private, link-local, and other restricted IP address ranges. However, IP addresses were compared against the blocked ranges without first normalising IPv4-mapped IPv6 addresses.\n\nAn authenticated attacker able to invoke the module could supply an IPv4-mapped IPv6 address, such as:\n\nhttp://[::ffff:127.0.0.1]/\nhttp://[::ffff:169.254.169.254]/\n\nAlternatively, the attacker could use a hostname that resolves to an IPv4-mapped IPv6 address. These addresses were treated as IPv6 addresses and therefore did not match the corresponding blocked IPv4 ranges.\n\nSuccessful exploitation could cause the misp-modules server to connect to services available through its loopback interface, internal network, or link-local network. This could expose internal web services, administrative interfaces, or cloud instance metadata, with retrieved content potentially returned to the attacker as converted Markdown.\n\nThe vulnerability has been addressed by normalising IPv4-mapped IPv6 addresses to their underlying IPv4 representation before applying the blocked-range checks. URLs without a valid hostname are now also rejected."
    },
    {
      "lang": "es",
      "value": "Una omisión de protección de falsificación de petición del lado del servidor (SSRF) existía en el módulo de expansión html_to_markdown de misp-modules.\n\nEl módulo intenta prevenir peticiones a rangos de dirección IP de loopback, privados, link-local y otros restringidos. Sin embargo, las direcciones IP se compararon contra los rangos bloqueados sin normalizar primero las direcciones IPv6 mapeadas a IPv4.\n\nUn atacante autenticado capaz de invocar el módulo podría suministrar una dirección IPv6 mapeada a IPv4, como:\n\nhttp://[::ffff:127.0.0.1]/\nhttp://[::ffff:169.254.169.254]/\n\nAlternativamente, el atacante podría usar un nombre de host que se resuelve en una dirección IPv6 mapeada a IPv4. Estas direcciones fueron tratadas como direcciones IPv6 y por lo tanto no coincidieron con los rangos IPv4 bloqueados correspondientes.\n\nLa explotación exitosa podría causar que el servidor misp-modules se conectara a servicios disponibles a través de su interfaz de loopback, red interna o red link-local. Esto podría exponer servicios web internos, interfaces administrativas o metadatos de instancias en la nube, con el contenido recuperado potencialmente devuelto al atacante como Markdown convertido.\n\nLa vulnerabilidad ha sido abordada normalizando las direcciones IPv6 mapeadas a IPv4 a su representación IPv4 subyacente antes de aplicar las comprobaciones de rango bloqueado. Las URL sin un nombre de host válido ahora también son rechazadas."
    }
  ],
  "affected": [
    {
      "source": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
      "affectedData": [
        {
          "vendor": "misp",
          "product": "misp-modules",
          "defaultStatus": "unaffected",
          "repo": "https://github.com/MISP/misp-modules/",
          "versions": [
            {
              "version": "0",
              "lessThanOrEqual": "v3.0.8",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/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:Y/R:X/V:X/RE:M/U:Green",
          "baseScore": 8.3,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "HIGH",
          "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": "YES",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "MODERATE",
          "providerUrgency": "GREEN"
        }
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-14T14:16:43.435933Z",
          "id": "CVE-2026-62143",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/MISP/misp-modules/commit/3bae4108a3ba1e507727d5264697fd7303ba0b89",
      "source": "5a6e4751-2f3f-4070-9419-94fb35b644e8"
    }
  ]
}