« Volver al listado

CVE-2026-45364

Estado: AplazadaAlta (7.3)—

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.4.17 and 1.5.0-beta.9, Better Auth's HTTP rate limiter keyed each request by the exact textual IP address it received in x-forwarded-for (or the configured IP-bearing header). IPv6 clients controlling a typical /64 allocation could rotate through 2^64 distinct source addresses without exhausting the per-address counter, defeating rate limiting on /sign-in/email, /sign-up/email, /forget-password, and every other path the limiter protects. The same bug allowed a single client to vary the textual encoding of one IPv6 address (uppercase, compression, IPv4-mapped, hex-encoded IPv4-in-IPv6) and produce multiple distinct keys. This vulnerability is fixed in 1.4.17 and 1.5.0-beta.9.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Red sin privilegios (AV:N/PR:N): T1190. Evasión de rate limiter permite DoS por agotamiento (C:L/A:L) e intentos de fuerza bruta masivos contra autenticación sin límite.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Filter Network TrafficVulnerability ScanningUser Account ManagementPrivileged Account ManagementPassword PoliciesNetwork Segmentation

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Better-auth — Better AuthAI

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-45364",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-45364",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-05-29T19:05:14.121201Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.3,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "LOW",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 3.4,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "better-auth",
          "product": "better-auth",
          "versions": [
            {
              "status": "affected",
              "version": "< 1.4.17"
            },
            {
              "status": "affected",
              "version": ">= 1.5.0-beta.1, < 1.5.0-beta.9"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-05-28T22:17:00.633",
  "references": [
    {
      "url": "https://github.com/better-auth/better-auth/commit/43e719bcc0c223c7079fa0c611a9cf7ea1188254",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/better-auth/better-auth/commit/57af0f7b910dcf7b1a5c0615d10b9bd56bb69bef",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/better-auth/better-auth/pull/7470",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/better-auth/better-auth/pull/7509",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/better-auth/better-auth/security/advisories/GHSA-p6v2-xcpg-h6xw",
      "source": "security-advisories@github.com"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-307"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Better Auth is an authentication and authorization library for TypeScript. Prior to 1.4.17 and 1.5.0-beta.9, Better Auth's HTTP rate limiter keyed each request by the exact textual IP address it received in x-forwarded-for (or the configured IP-bearing header). IPv6 clients controlling a typical /64 allocation could rotate through 2^64 distinct source addresses without exhausting the per-address counter, defeating rate limiting on /sign-in/email, /sign-up/email, /forget-password, and every other path the limiter protects. The same bug allowed a single client to vary the textual encoding of one IPv6 address (uppercase, compression, IPv4-mapped, hex-encoded IPv4-in-IPv6) and produce multiple distinct keys. This vulnerability is fixed in 1.4.17 and 1.5.0-beta.9."
    },
    {
      "lang": "es",
      "value": "Better Auth es una biblioteca de autenticación y autorización para TypeScript. Antes de 1.4.17 y 1.5.0-beta.9, el limitador de tasa HTTP de Better Auth identificaba cada solicitud por la dirección IP textual exacta que recibía en x-forwarded-for (o el encabezado configurado que contenía la IP). Clientes IPv6 que controlaban una asignación /64 típica podían rotar a través de 2^64 direcciones de origen distintas sin agotar el contador por dirección, eludiendo la limitación de tasa en /sign-in/email, /sign-up/email, /forget-password y cualquier otra ruta que el limitador protegiera. El mismo error permitía a un único cliente variar la codificación textual de una dirección IPv6 (mayúsculas, compresión, mapeada a IPv4, IPv4 codificada en hexadecimal en IPv6) y producir múltiples claves distintas. Esta vulnerabilidad está corregida en 1.4.17 y 1.5.0-beta.9."
    }
  ],
  "lastModified": "2026-07-21T10:10:00.103",
  "sourceIdentifier": "security-advisories@github.com"
}