{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0.1.0"
              },
              {
                "fixed": "2.4.1"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "e6017b492b8ef55e24fd08dea45ce11780d7b4f7"
            }
          ],
          "repo": "https://github.com/ueberauth/guardian",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-xqch-c77q-rgh5"
  ],
  "database_specific": {
    "cna_assigner": "EEF",
    "cwe_ids": [
      "CWE-770"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54894.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "7126fa433afc2563fcac0c9aa35193965f8fd5f8"
          },
          {
            "fixed": "2952657e42e6341a67e6aaad09d8f0b40ae917cb"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "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_\u003cinput\u003e\", 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.",
  "id": "CVE-2026-54894",
  "modified": "2026-08-04T11:31:01.372757733Z",
  "published": "2026-08-01T18:46:05.861Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-54894.html"
    },
    {
      "type": "WEB",
      "url": "https://github.com"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-54894"
    },
    {
      "type": "WEB",
      "url": "https://repo.hex.pm"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54894.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/ueberauth/guardian/security/advisories/GHSA-xqch-c77q-rgh5"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-54894"
    },
    {
      "type": "FIX",
      "url": "https://github.com/ueberauth/guardian/commit/2952657e42e6341a67e6aaad09d8f0b40ae917cb"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/ueberauth/guardian"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Atom-table exhaustion denial of service in Guardian via unbounded atom creation from binary keys"
}