CVE-2026-82760

Estado: AplazadaAlta (8.2)—

Inefficient Algorithmic Complexity vulnerability in team-alembic AshAuthentication allows an unauthenticated attacker to exhaust CPU and memory via an oversized base62 segment in a submitted API key.

AshAuthentication.Base.decode62/1 in lib/ash_authentication/base.ex splits its argument into one binary per character and folds it with charval62/2, which recomputes Integer.pow(62, index) at every position instead of accumulating by Horner's method, so cost grows roughly cubically in the input length. bindecode62/1 in the same module is quadratic through Integer.undigits/2 and Integer.digits/2.

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Neither function caps byte_size/1, and AshAuthentication.Strategy.ApiKey.SignInPreparation passes the underscore-separated segments of the submitted key straight into both, before any key lookup and without prior authentication. The surrounding rescue clauses catch exceptions, not CPU or memory exhaustion.

This issue affects ash_authentication: from 4.8.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.

CVSS

Versión: 4.0
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/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
Puntuación base: 8.2

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.74%
Percentil entre todas las CVEs puntuadas: 53
Fecha de la puntuación: 6/10/2026

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.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access85 %
Impacto principalT1499.004 Application or System Exploitationimpact90 %
Impacto secundarioT1499.001 OS Exhaustion Floodimpact80 %

API key en endpoint remoto (AV:N, sin autenticación previa) susceptible a ataque algorítmico que agota CPU/memoria; decodificación ineficiente (O(n³)) por sobrecarga de funciones sin límite de tamaño.

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 Traffic Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Application 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.

Alembic — ASH Authentication^AI

CWE

CWE-407

Referencias

JSON original (NVD)

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  "id": "CVE-2026-82760",
  "cveTags": [],
  "metrics": {
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          "options": [
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          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/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",
          "exploitMaturity": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED",
          "userInteraction": "NONE",
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          "modifiedAttackVector": "NOT_DEFINED",
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          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "NONE",
          "vulnConfidentialityImpact": "NONE",
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          "modifiedAttackRequirements": "NOT_DEFINED",
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          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
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  "affected": [
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      "affectedData": [
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          "cpes": [
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          ],
          "repo": "https://github.com/team-alembic/ash_authentication",
          "vendor": "team-alembic",
          "modules": [
            "'Elixir.AshAuthentication.Base'",
            "'Elixir.AshAuthentication.Strategy.ApiKey.SignInPreparation'"
          ],
          "product": "ash_authentication",
          "versions": [
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              "name": "'Elixir.AshAuthentication.Strategy.ApiKey.SignInPreparation':prepare/3"
            }
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        },
        {
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            },
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            },
            {
              "name": "'Elixir.AshAuthentication.Strategy.ApiKey.SignInPreparation':prepare/3"
            }
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        }
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    }
  ],
  "published": "2026-09-17T14:17:33.237",
  "references": [
    {
      "url": "https://cna.erlef.org/cves/CVE-2026-82760.html",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
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    {
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-82760",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
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      "description": [
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          "lang": "en",
          "value": "CWE-407"
        }
      ]
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  "descriptions": [
    {
      "lang": "en",
      "value": "Inefficient Algorithmic Complexity vulnerability in team-alembic AshAuthentication allows an unauthenticated attacker to exhaust CPU and memory via an oversized base62 segment in a submitted API key.\n\nAshAuthentication.Base.decode62/1 in lib/ash_authentication/base.ex splits its argument into one binary per character and folds it with charval62/2, which recomputes Integer.pow(62, index) at every position instead of accumulating by Horner's method, so cost grows roughly cubically in the input length. bindecode62/1 in the same module is quadratic through Integer.undigits/2 and Integer.digits/2. Neither function caps byte_size/1, and AshAuthentication.Strategy.ApiKey.SignInPreparation passes the underscore-separated segments of the submitted key straight into both, before any key lookup and without prior authentication. The surrounding rescue clauses catch exceptions, not CPU or memory exhaustion.\n\nThis issue affects ash_authentication: from 4.8.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14."
    }
  ],
  "lastModified": "2026-09-18T18:16:18.527",
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
}