« Volver al listado

CVE-2026-77561

Estado: AplazadaMedia (5.3)—

Tinyauth is an authentication and authorization server. Prior to 5.1.0, an unauthenticated remote attacker can send POST /api/user/login requests with 257 distinct nonexistent usernames to fill MaxLoginAttemptRecords and activate a global login lockdown. internal/controller/user_controller.go loginHandler passes each attacker-controlled identifier to internal/service/auth_service.go RecordLoginAttempt, which invokes lockdownMode after the map reaches its cap. IsAccountLocked checks that global state before validating unrelated accounts, causing valid users to receive HTTP 429 until auth.loginTimeout expires, approximately 300 seconds by default. The attack can be repeated, but existing authenticated sessions are not invalidated. This issue is fixed in version 5.1.0.

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.

Atacante remoto unauthenticated explota lógica de bloqueo de login (CWE-307: falta de límite de intentos) enviando POST a /api/user/login con 257 usuarios ficticios, activando lockdown global que rechaza peticiones válidas (HTTP 429) ~300 seg, causando negación de servicio.

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 ScanningPrivileged Account ManagementNetwork SegmentationLimit Access to Resource Over NetworkApplication Isolation and Sandboxing

Tecnologías afectadas (1)

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

Tinyauth — TinyauthAI

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-77561",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-77561",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-24T22:22:48.336829Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.3,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "LOW",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "tinyauthapp",
          "product": "tinyauth",
          "versions": [
            {
              "status": "affected",
              "version": "< 5.1.0"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-09-21T17:18:52.943",
  "references": [
    {
      "url": "https://github.com/tinyauthapp/tinyauth/commit/654b5cc436fc67865c1f55edf9ba9fbded50b74f",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/tinyauthapp/tinyauth/commit/dade1e2c8f27a23df56ac216dcaf4b37081698e7",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/tinyauthapp/tinyauth/pull/1008",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/tinyauthapp/tinyauth/pull/943",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/tinyauthapp/tinyauth/releases/tag/v5.1.0",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/tinyauthapp/tinyauth/security/advisories/GHSA-9xhm-w3wj-xhqh",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/tinyauthapp/tinyauth/security/advisories/GHSA-9xhm-w3wj-xhqh",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-307"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Tinyauth is an authentication and authorization server. Prior to 5.1.0, an unauthenticated remote attacker can send POST /api/user/login requests with 257 distinct nonexistent usernames to fill MaxLoginAttemptRecords and activate a global login lockdown. internal/controller/user_controller.go loginHandler passes each attacker-controlled identifier to internal/service/auth_service.go RecordLoginAttempt, which invokes lockdownMode after the map reaches its cap. IsAccountLocked checks that global state before validating unrelated accounts, causing valid users to receive HTTP 429 until auth.loginTimeout expires, approximately 300 seconds by default. The attack can be repeated, but existing authenticated sessions are not invalidated. This issue is fixed in version 5.1.0."
    }
  ],
  "lastModified": "2026-09-24T23:19:02.063",
  "sourceIdentifier": "security-advisories@github.com"
}