CVE-2026-55736

Full vulnerability record from the local CVENow database.

Description

Improperly Controlled Modification of Dynamically-Determined Object Attributes vulnerability in ash-project ash allows a user to set the value of a private action argument that is intended to be controlled only by trusted server-side code. Action arguments declared with public?: false are meant to be set internally (for example via Ash.Changeset.set_private_argument/3) and must not be settable from end-user input. When a changeset is built from a parameter map, Ash filters out private arguments, but the filtering is incomplete. In the regular changeset path (for_create, for_update, for_destroy), private arguments are stripped only when the parameter key is an atom. When the key is a binary (string), as is the case for user-supplied parameters, the private argument is kept and the user controls its value. In the atomic path (Ash.Changeset.fully_atomic_changeset/4, also reached through atomic and bulk updates), private arguments are not stripped at all, regardless of whether the key is an atom or a binary. An attacker who can submit parameters to an action that defines a private argument can therefore inject a value for that argument. Depending on how the application uses the argument (for example an acting_user_id driving authorization or record ownership), this can lead to an integrity violation or privilege escalation. This issue affects ash: from 3.0.0 before 3.29.3.

Severity

MEDIUM

CVSS score

5.9 (v4.0)

Vulnerability status

Deferred

Source identifier

6b3ad84c-e1a6-4bf7-a703-f496b71e49db

Published

2026-06-23 19:17:12.287000

Last modified

2026-10-25 23:10:00.167000

View original CVE JSON

{
  "id": "CVE-2026-55736",
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
  "published": "2026-06-23T19:17:12.287",
  "lastModified": "2026-10-25T23:10:00.167",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Improperly Controlled Modification of Dynamically-Determined Object Attributes vulnerability in ash-project ash allows a user to set the value of a private action argument that is intended to be controlled only by trusted server-side code.\n\nAction arguments declared with public?: false are meant to be set internally (for example via Ash.Changeset.set_private_argument/3) and must not be settable from end-user input. When a changeset is built from a parameter map, Ash filters out private arguments, but the filtering is incomplete.\n\nIn the regular changeset path (for_create, for_update, for_destroy), private arguments are stripped only when the parameter key is an atom. When the key is a binary (string), as is the case for user-supplied parameters, the private argument is kept and the user controls its value. In the atomic path (Ash.Changeset.fully_atomic_changeset/4, also reached through atomic and bulk updates), private arguments are not stripped at all, regardless of whether the key is an atom or a binary.\n\nAn attacker who can submit parameters to an action that defines a private argument can therefore inject a value for that argument. Depending on how the application uses the argument (for example an acting_user_id driving authorization or record ownership), this can lead to an integrity violation or privilege escalation.\n\nThis issue affects ash: from 3.0.0 before 3.29.3."
    },
    {
      "lang": "es",
      "value": "La vulnerabilidad de Modificación Incontrolada de Atributos de Objeto Determinados Dinámicamente en ash-project ash permite a un usuario establecer el valor de un argumento de acción privado que está destinado a ser controlado solo por código de lado del servidor de confianza.\n\nLos argumentos de acción declarados con public?: false están destinados a ser establecidos internamente (por ejemplo, a través de Ash.Changeset.set_private_argument/3) y no deben ser configurables desde la entrada del usuario final. Cuando un changeset se construye a partir de un mapa de parámetros, Ash filtra los argumentos privados, pero el filtrado es incompleto.\n\nEn la ruta regular del changeset (for_create, for_update, for_destroy), los argumentos privados se eliminan solo cuando la clave del parámetro es un átomo. Cuando la clave es un binario (cadena), como es el caso de los parámetros proporcionados por el usuario, el argumento privado se mantiene y el usuario controla su valor. En la ruta atómica (Ash.Changeset.fully_atomic_changeset/4, también alcanzada a través de actualizaciones atómicas y masivas), los argumentos privados no se eliminan en absoluto, independientemente de si la clave es un átomo o un binario.\n\nUn atacante que puede enviar parámetros a una acción que define un argumento privado puede, por lo tanto, inyectar un valor para ese argumento. Dependiendo de cómo la aplicación utilice el argumento (por ejemplo, un acting_user_id que impulsa la autorización o la propiedad del registro), esto puede conducir a una violación de la integridad o a una escalada de privilegios.\n\nEste problema afecta a ash: desde 3.0.0 antes de 3.29.3."
    }
  ],
  "affected": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "affectedData": [
        {
          "vendor": "ash-project",
          "product": "ash",
          "defaultStatus": "unaffected",
          "collectionURL": "https://repo.hex.pm",
          "packageName": "ash",
          "cpes": [
            "cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*"
          ],
          "modules": [
            "'Elixir.Ash.Changeset'"
          ],
          "programFiles": [
            "lib/ash/changeset/changeset.ex"
          ],
          "programRoutines": [
            {
              "name": "'Elixir.Ash.Changeset':cast_params/4"
            },
            {
              "name": "'Elixir.Ash.Changeset':get_action_argument/2"
            },
            {
              "name": "'Elixir.Ash.Changeset':atomic_params/4"
            },
            {
              "name": "'Elixir.Ash.Changeset':has_argument?/2"
            }
          ],
          "repo": "https://github.com/ash-project/ash",
          "packageURL": "pkg:hex/ash",
          "versions": [
            {
              "version": "3.0.0",
              "lessThan": "3.29.3",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "ash-project",
          "product": "ash",
          "defaultStatus": "unaffected",
          "collectionURL": "https://github.com",
          "packageName": "ash-project/ash",
          "cpes": [
            "cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*"
          ],
          "modules": [
            "'Elixir.Ash.Changeset'"
          ],
          "programFiles": [
            "lib/ash/changeset/changeset.ex"
          ],
          "programRoutines": [
            {
              "name": "'Elixir.Ash.Changeset':cast_params/4"
            },
            {
              "name": "'Elixir.Ash.Changeset':get_action_argument/2"
            },
            {
              "name": "'Elixir.Ash.Changeset':atomic_params/4"
            },
            {
              "name": "'Elixir.Ash.Changeset':has_argument?/2"
            }
          ],
          "repo": "https://github.com/ash-project/ash",
          "packageURL": "pkg:github/ash-project/ash",
          "versions": [
            {
              "version": "5967ed3a483ab949866e6d7b043b043e61703f17",
              "lessThan": "d9b3100219b3ea86d73202bf7368c03a7688efea",
              "versionType": "git",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/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": 5.9,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "HIGH",
          "vulnAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "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"
        }
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-09T14:53:04.134939Z",
          "id": "CVE-2026-55736",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-915"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://cna.erlef.org/cves/CVE-2026-55736.html",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/ash-project/ash/commit/d9b3100219b3ea86d73202bf7368c03a7688efea",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/ash-project/ash/security/advisories/GHSA-f4hc-ppw9-4hhw",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-55736",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/ash-project/ash/security/advisories/GHSA-f4hc-ppw9-4hhw",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}