{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-55733",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-55733",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-08-01T18:46:12.113Z",
    "updatedAt": "2026-08-03T16:50:53.942Z",
    "importedAt": "2026-10-24T01:58:20.586Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "Atom-table exhaustion denial of service in Guardian permissions AtomEncoding via unbounded atom creation",
      "summary": "Allocation of Resources Without Limits or Throttling in ueberauth guardian allows denial of service via unbounded atom creation from attacker-controlled binary input.\n\nGuardian.Permissions.AtomEncoding encodes permission scopes by passing arbitrary binaries to String.to_atom/1. When encode/3 in lib/guardian/permissions/atom_encoding.ex is called with a list, each binary entry is handled by the encode_value/3 binary clause, which calls String.to_atom(value) with no allow-list check. The perm_set argument (the application's small, finite set of legitimate permission names) is discarded, so any external string flows straight into atom creation. This encoder is selected with use Guardian.Permissions, encoding: Guardian.Permissions.AtomEncoding and reached through the imported encode/3 entry point.\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 funnels attacker-influenced permission scopes (from a request body, a JWT claim, or other external input) into encode/3 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 with system_limit, taking down every application running on it.\n\nThe default encoder is Guardian.Permissions.BitwiseEncoding, which is not affected.\n\nThis issue affects guardian: from 2.0.0 before 2.4.1.",
      "affected": [
        {
          "vendor": "ueberauth",
          "product": "guardian",
          "packageName": "guardian",
          "collectionURL": "https://repo.hex.pm",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "2.0.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "2.4.1"
            }
          ]
        },
        {
          "vendor": "ueberauth",
          "product": "guardian",
          "packageName": "ueberauth/guardian",
          "collectionURL": "https://github.com",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "b7a6128ca4d0ffb7f7df5219dd982304ff9d6802",
              "status": "affected",
              "versionType": "git",
              "lessThan": "9cd268557846aa4c3ad53566c08f2c190ee5513f"
            }
          ]
        }
      ]
    }
  }
}