CVE-2026-54894

Full vulnerability record from the local CVENow database.

Description

Allocation of Resources Without Limits or Throttling in ueberauth guardian allows denial of service via unbounded atom creation from attacker-influenced binary input. Guardian.Plug.Keys derives connection and session namespace keys by passing arbitrary binaries to String.to_atom/1. base_key/1 in lib/guardian/plug/keys.ex converts any binary into the atom :"guardian_<input>", and the derived helpers claims_key/1, resource_key/1, and token_key/1 create a second atom on top of that. key_from_other/1 likewise converts a regex-captured binary through String.to_atom/1. The public specs advertise String.t() as a valid argument, so passing a string is documented usage, and higher-level entry points such as Guardian.Plug.current_token(conn, key: key) thread the caller-supplied key straight into these functions. String.to_atom/1 creates a brand-new atom for every previously unseen binary, atoms are never garbage collected, and the BEAM atom table is fixed at roughly 1,048,576 entries by default. An application that routes attacker-influenced data (a tenant identifier, header, or other request input) into a Guardian key therefore mints one permanent atom per distinct value. A modest stream of varied, unauthenticated input permanently consumes the atom table and crashes the BEAM node, taking down every application running on it. This issue affects guardian: from 0.1.0 before 2.4.1.

Severity

MEDIUM

CVSS score

6.9 (v4.0)

Vulnerability status

Analyzed

Source identifier

6b3ad84c-e1a6-4bf7-a703-f496b71e49db

Published

2026-08-01 19:16:41.977000

Last modified

2026-10-23 22:10:00.160000

View original CVE JSON

{
  "id": "CVE-2026-54894",
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
  "published": "2026-08-01T19:16:41.977",
  "lastModified": "2026-10-23T22:10:00.160",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Allocation of Resources Without Limits or Throttling in ueberauth guardian allows denial of service via unbounded atom creation from attacker-influenced binary input.\n\nGuardian.Plug.Keys derives connection and session namespace keys by passing arbitrary binaries to String.to_atom/1. base_key/1 in lib/guardian/plug/keys.ex converts any binary into the atom :\"guardian_<input>\", and the derived helpers claims_key/1, resource_key/1, and token_key/1 create a second atom on top of that. key_from_other/1 likewise converts a regex-captured binary through String.to_atom/1. The public specs advertise String.t() as a valid argument, so passing a string is documented usage, and higher-level entry points such as Guardian.Plug.current_token(conn, key: key) thread the caller-supplied key straight into these functions.\n\nString.to_atom/1 creates a brand-new atom for every previously unseen binary, atoms are never garbage collected, and the BEAM atom table is fixed at roughly 1,048,576 entries by default. An application that routes attacker-influenced data (a tenant identifier, header, or other request input) into a Guardian key therefore mints one permanent atom per distinct value. A modest stream of varied, unauthenticated input permanently consumes the atom table and crashes the BEAM node, taking down every application running on it.\n\nThis issue affects guardian: from 0.1.0 before 2.4.1."
    },
    {
      "lang": "es",
      "value": "La asignación de recursos sin límites ni estrangulamiento en ueberauth guardian permite la denegación de servicio a través de la creación ilimitada de átomos a partir de entrada binaria influenciada por el atacante.\n\nGuardian.Plug.Keys deriva claves de espacio de nombres de conexión y de sesión pasando binarios arbitrarios a String.to_atom/1. base_key/1 en lib/guardian/plug/keys.ex convierte cualquier binario en el átomo :“guardian_[input]”, y las funciones auxiliares derivadas claims_key/1, resource_key/1 y token_key/1 crean un segundo átomo además de eso. key_from_other/1 de manera similar convierte un binario capturado por regex a través de String.to_atom/1. Las especificaciones públicas anuncian String.t() como un argumento válido, por lo que pasar una cadena es un uso documentado, y los puntos de entrada de nivel superior, como Guardian.Plug.current_token(conn, key: key), pasan la clave proporcionada por el llamador directamente a estas funciones.\n\nString.to_atom/1 crea un átomo completamente nuevo para cada binario no visto anteriormente, los átomos nunca son recolectados por el recolector de basura, y la tabla de átomos de BEAM está fijada en aproximadamente 1.048.576 entradas por defecto. Una aplicación que enruta datos influenciados por el atacante (un identificador de inquilino, encabezado u otra entrada de solicitud) en una clave de Guardian, por lo tanto, acuña un átomo permanente por cada valor distinto. Un flujo modesto de entrada variada y no autenticada consume permanentemente la tabla de átomos y bloquea el nodo BEAM, derribando todas las aplicaciones que se ejecutan en él.\n\nEste problema afecta a guardian: desde 0.1.0 antes de 2.4.1."
    }
  ],
  "affected": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "affectedData": [
        {
          "vendor": "ueberauth",
          "product": "guardian",
          "defaultStatus": "unaffected",
          "collectionURL": "https://repo.hex.pm",
          "packageName": "guardian",
          "cpes": [
            "cpe:2.3:a:ueberauth:guardian:*:*:*:*:*:*:*:*"
          ],
          "modules": [
            "'Elixir.Guardian.Plug.Keys'"
          ],
          "programFiles": [
            "lib/guardian/plug/keys.ex"
          ],
          "programRoutines": [
            {
              "name": "'Elixir.Guardian.Plug.Keys':base_key/1"
            },
            {
              "name": "'Elixir.Guardian.Plug.Keys':claims_key/1"
            },
            {
              "name": "'Elixir.Guardian.Plug.Keys':resource_key/1"
            },
            {
              "name": "'Elixir.Guardian.Plug.Keys':token_key/1"
            },
            {
              "name": "'Elixir.Guardian.Plug.Keys':key_from_other/1"
            }
          ],
          "repo": "https://github.com/ueberauth/guardian",
          "packageURL": "pkg:hex/guardian",
          "versions": [
            {
              "version": "0.1.0",
              "lessThan": "2.4.1",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "ueberauth",
          "product": "guardian",
          "defaultStatus": "unaffected",
          "collectionURL": "https://github.com",
          "packageName": "ueberauth/guardian",
          "cpes": [
            "cpe:2.3:a:ueberauth:guardian:*:*:*:*:*:*:*:*"
          ],
          "modules": [
            "'Elixir.Guardian.Plug.Keys'"
          ],
          "programFiles": [
            "lib/guardian/plug/keys.ex"
          ],
          "programRoutines": [
            {
              "name": "'Elixir.Guardian.Plug.Keys':base_key/1"
            },
            {
              "name": "'Elixir.Guardian.Plug.Keys':claims_key/1"
            },
            {
              "name": "'Elixir.Guardian.Plug.Keys':resource_key/1"
            },
            {
              "name": "'Elixir.Guardian.Plug.Keys':token_key/1"
            },
            {
              "name": "'Elixir.Guardian.Plug.Keys':key_from_other/1"
            }
          ],
          "repo": "https://github.com/ueberauth/guardian",
          "packageURL": "pkg:github/ueberauth/guardian",
          "versions": [
            {
              "version": "7126fa433afc2563fcac0c9aa35193965f8fd5f8",
              "lessThan": "2952657e42e6341a67e6aaad09d8f0b40ae917cb",
              "versionType": "git",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
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          "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/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": 6.9,
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          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "HIGH",
          "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": "Primary",
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          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
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    "ssvcV203": [
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        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-08-03T17:49:32.217048Z",
          "id": "CVE-2026-54894",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
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  "weaknesses": [
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      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
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  "configurations": [
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      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
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              "vulnerable": true,
              "criteria": "cpe:2.3:a:ueberauth:guardian:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "2.4.1",
              "matchCriteriaId": "5C4F81E1-8FC4-4B7E-93A3-A5A0BD523959"
            }
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        }
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  "references": [
    {
      "url": "https://cna.erlef.org/cves/CVE-2026-54894.html",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "tags": [
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      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
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}