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Unbounded atom creation from unsigned LogoutResponse status codes in esaml allows atom table exhaustion

Type: advisorySource: Official CVE List1 source record

Allocation of Resources Without Limits or Throttling vulnerability in esaml in dropbox esaml allows an unauthenticated attacker to exhaust the Erlang VM atom table and crash the node via unsigned LogoutResponse messages. esaml:status_code_map/1 in src/esaml.erl maps any StatusCode value it does not recognize to an atom with list_to_atom/1 on the last colon-separated segment of the URN. esaml_sp:validate_logout_response/2 verifies a signature only when the message carries one, so an unsigned LogoutResponse posted to the single-logout endpoint reaches esaml:decode_logout_response/1 and mints one permanent atom per distinct status value. Atoms are never reclaimed and the VM caps the atom table at about one million entries, so an attacker who posts that many distinct values aborts the node. This issue affects esaml: from 0.1.0 onward.

Announced Source revision 1
Original source ↗

CVE-2026-86696

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-86696

esaml

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

esaml

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

esaml

Source reference: /containers/cna/affected/2/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

esaml

Source reference: /containers/cna/affected/3/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "cpes": [
      "cpe:2.3:a:handnot2:esaml:*:*:*:*:*:*:*:*"
    ],
    "repo": "https://github.com/handnot2/esaml",
    "vendor": "handnot2",
    "modules": [
      "esaml",
      "esaml_sp",
      "esaml_cowboy"
    ],
    "product": "esaml",
    "versions": [
      {
        "status": "affected",
        "version": "be692b56245071899757afa7ef47e43593d3de96",
        "lessThan": "*",
        "versionType": "git"
      }
    ],
    "packageURL": "pkg:github/handnot2/esaml",
    "packageName": "handnot2/esaml",
    "programFiles": [
      "src/esaml.erl",
      "src/esaml_sp.erl",
      "src/esaml_cowboy.erl"
    ],
    "collectionURL": "https://github.com",
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "esaml:status_code_map/1"
      },
      {
        "name": "esaml:decode_logout_response/1"
      },
      {
        "name": "esaml_sp:validate_logout_response/2"
      },
      {
        "name": "esaml_cowboy:validate_logout/2"
      }
    ]
  },
  {
    "cpes": [
      "cpe:2.3:a:arekinath:esaml:*:*:*:*:*:*:*:*"
    ],
    "repo": "https://github.com/arekinath/esaml",
    "vendor": "arekinath",
    "modules": [
      "esaml",
      "esaml_sp",
      "esaml_cowboy"
    ],
    "product": "esaml",
    "versions": [
      {
        "status": "affected",
        "version": "be692b56245071899757afa7ef47e43593d3de96",
        "lessThan": "*",
        "versionType": "git"
      }
    ],
    "packageURL": "pkg:github/arekinath/esaml",
    "packageName": "arekinath/esaml",
    "programFiles": [
      "src/esaml.erl",
      "src/esaml_sp.erl",
      "src/esaml_cowboy.erl"
    ],
    "collectionURL": "https://github.com",
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "esaml:status_code_map/1"
      },
      {
        "name": "esaml:decode_logout_response/1"
      },
      {
        "name": "esaml_sp:validate_logout_response/2"
      },
      {
        "name": "esaml_cowboy:validate_logout/2"
      }
    ]
  },
  {
    "cpes": [
      "cpe:2.3:a:dropbox:esaml:*:*:*:*:*:*:*:*"
    ],
    "repo": "https://github.com/dropbox/esaml",
    "vendor": "dropbox",
    "modules": [
      "esaml",
      "esaml_sp",
      "esaml_cowboy"
    ],
    "product": "esaml",
    "versions": [
      {
        "status": "affected",
        "version": "0.1.0",
        "lessThan": "*",
        "versionType": "semver"
      }
    ],
    "packageURL": "pkg:hex/esaml",
    "packageName": "esaml",
    "programFiles": [
      "src/esaml.erl",
      "src/esaml_sp.erl",
      "src/esaml_cowboy.erl"
    ],
    "collectionURL": "https://repo.hex.pm",
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "esaml:status_code_map/1"
      },
      {
        "name": "esaml:decode_logout_response/1"
      },
      {
        "name": "esaml_sp:validate_logout_response/2"
      },
      {
        "name": "esaml_cowboy:validate_logout/2"
      }
    ]
  },
  {
    "cpes": [
      "cpe:2.3:a:dropbox:esaml:*:*:*:*:*:*:*:*"
    ],
    "repo": "https://github.com/dropbox/esaml",
    "vendor": "dropbox",
    "modules": [
      "esaml",
      "esaml_sp",
      "esaml_cowboy"
    ],
    "product": "esaml",
    "versions": [
      {
        "status": "affected",
        "version": "be692b56245071899757afa7ef47e43593d3de96",
        "lessThan": "*",
        "versionType": "git"
      }
    ],
    "packageURL": "pkg:github/dropbox/esaml",
    "packageName": "dropbox/esaml",
    "programFiles": [
      "src/esaml.erl",
      "src/esaml_sp.erl",
      "src/esaml_cowboy.erl"
    ],
    "collectionURL": "https://github.com",
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "esaml:status_code_map/1"
      },
      {
        "name": "esaml:decode_logout_response/1"
      },
      {
        "name": "esaml_sp:validate_logout_response/2"
      },
      {
        "name": "esaml_cowboy:validate_logout/2"
      }
    ]
  }
]
Related CVEs
CVE-2026-86696

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#50141 · Revision 1
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Publisher date
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