eef-cve-2026-82760

{
  "affected": [
    {
      "database_specific": {
        "source": "https://cna.erlef.org/osv/EEF-CVE-2026-82760.json"
      },
      "package": {
        "ecosystem": "Hex",
        "name": "ash_authentication",
        "purl": "pkg:hex/ash_authentication"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.8.0"
            },
            {
              "fixed": "4.15.0"
            }
          ],
          "type": "SEMVER"
        },
        {
          "events": [
            {
              "introduced": "5.0.0-rc.0"
            },
            {
              "fixed": "5.0.0-rc.14"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "versions": [
        "4.10.0",
        "4.11.0",
        "4.12.0",
        "4.13.0",
        "4.13.1",
        "4.13.2",
        "4.13.3",
        "4.13.4",
        "4.13.5",
        "4.13.6",
        "4.13.7",
        "4.14.0",
        "4.14.1",
        "4.14.2",
        "4.8.0",
        "4.8.1",
        "4.8.2",
        "4.8.3",
        "4.8.5",
        "4.8.6",
        "4.8.7",
        "4.9.0",
        "4.9.1",
        "4.9.2",
        "4.9.3",
        "4.9.4",
        "4.9.5",
        "4.9.6",
        "4.9.7",
        "4.9.8",
        "4.9.9",
        "5.0.0-rc.0",
        "5.0.0-rc.1",
        "5.0.0-rc.10",
        "5.0.0-rc.11",
        "5.0.0-rc.12",
        "5.0.0-rc.13",
        "5.0.0-rc.2",
        "5.0.0-rc.3",
        "5.0.0-rc.4",
        "5.0.0-rc.5",
        "5.0.0-rc.6",
        "5.0.0-rc.7",
        "5.0.0-rc.8",
        "5.0.0-rc.9"
      ]
    },
    {
      "database_specific": {
        "source": "https://cna.erlef.org/osv/EEF-CVE-2026-82760.json"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "f3a53f480088419788d5c3934af3131fa9066773"
            },
            {
              "fixed": "d5a5d4cb5cc17fbd6e2a120a6111b47accad4b8e"
            },
            {
              "fixed": "dfb19c897853686ab481c5e773f7a1a0c74dea04"
            }
          ],
          "repo": "https://github.com/team-alembic/ash_authentication",
          "type": "GIT"
        }
      ],
      "versions": [
        "v4.14.2",
        "v5.0.0-rc.13",
        "v4.14.1",
        "v5.0.0-rc.12",
        "v5.0.0-rc.11",
        "v5.0.0-rc.10",
        "v4.14.0",
        "v4.13.7",
        "5.0.0-rc.9",
        "5.0.0-rc.8",
        "v5.0.0-rc.7",
        "v5.0.0-rc.6",
        "v5.0.0-rc.5",
        "v5.0.0-rc.4",
        "v5.0.0-rc.3",
        "v5.0.0-rc.2",
        "v5.0.0-rc.1",
        "v5.0.0-rc.0",
        "v4.13.6",
        "v4.13.5",
        "v4.13.4",
        "v4.13.3",
        "v4.13.2",
        "v4.13.1",
        "v4.13.0",
        "v4.12.0",
        "v4.11.0",
        "v4.10.0",
        "v4.9.9",
        "v4.9.8",
        "v4.9.7",
        "v4.9.6",
        "v4.9.5",
        "v4.9.4",
        "v4.9.3",
        "v4.9.2",
        "v4.9.1",
        "v4.9.0",
        "v4.8.7",
        "v4.8.5",
        "v4.8.4",
        "v4.8.3",
        "v4.8.2",
        "v4.8.1",
        "v4.8.0"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-82760",
    "GHSA-q876-xr24-2mcx"
  ],
  "credits": [
    {
      "name": "Peter Ullrich",
      "type": "REPORTER"
    },
    {
      "name": "James Harton",
      "type": "REMEDIATION_DEVELOPER"
    },
    {
      "name": "Jonatan Männchen / EEF",
      "type": "ANALYST"
    }
  ],
  "database_specific": {
    "capec_ids": [
      "CAPEC-130"
    ],
    "cpe_ids": [
      "cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:*"
    ],
    "cwe_ids": [
      "CWE-407"
    ]
  },
  "details": "## Summary\n\nInefficient 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\n`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`. 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.",
  "id": "EEF-CVE-2026-82760",
  "modified": "2026-09-17T13:26:04.780684193Z",
  "published": "2026-09-17T13:08:46.382Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-q876-xr24-2mcx"
    },
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-82760.html"
    },
    {
      "type": "WEB",
      "url": "https://github.com/team-alembic/ash_authentication/commit/f3a53f480088419788d5c3934af3131fa9066773"
    },
    {
      "type": "FIX",
      "url": "https://github.com/team-alembic/ash_authentication/commit/d5a5d4cb5cc17fbd6e2a120a6111b47accad4b8e"
    },
    {
      "type": "FIX",
      "url": "https://github.com/team-alembic/ash_authentication/commit/dfb19c897853686ab481c5e773f7a1a0c74dea04"
    },
    {
      "type": "PACKAGE",
      "url": "https://hex.pm/packages/ash_authentication"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Superlinear base62 decoding exhausts CPU and memory in AshAuthentication API key sign-in"
}