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              "value": "Authorization Bypass Through User-Controlled Key vulnerability in ash-project ash allows a user of one tenant to read, overwrite and take over another tenant\u0027s records via an upserting create action.\n\nUnder attribute multitenancy, `Ash.Actions.Create` (`lib/ash/actions/create/create.ex`) and `Ash.Actions.Create.Bulk` (`lib/ash/actions/create/bulk.ex`) upserted on the primary key, or on an `all_tenants?` identity, without scoping the conflicting record to the request\u0027s tenant. A caller of a create action with `upsert? true` that accepts the primary key, supplying a record id from another tenant, updated that record\u0027s upsert fields and received all of its attributes in the result. With the default upsert fields the tenant attribute was written too, moving the record into the caller\u0027s tenant. Read and update policies do not run for upserts, and tenant-scoped create policies pass because the tenant is the caller\u0027s own.\n\nThis issue affects ash: from 1.22.0 before 3.37.2."
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\"https://github.com/ash-project/ash/commit/c9f0cdb31e7c084def05f3f5be69dd7bb7721754\", \"name\": \"Fix commit c9f0cdb in ash-project/ash\", \"tags\": [\"patch\"]}], \"workarounds\": [{\"lang\": \"en\", \"value\": \"Add upsert_condition expr(\u003ctenant attribute\u003e == ^tenant()) to every create action that upserts on the primary key or on an all_tenants? identity, and do not combine it with return_skipped_upsert?. An upsert into another tenant\u0027s record then fails with Ash.Error.Changes.StaleRecord (or is skipped in a bulk create) and leaves that record unchanged. This does not help on the Mnesia data layer, which ignores upsert conditions in affected versions.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eAdd \u003ccode\u003eupsert_condition expr(\u0026lt;tenant attribute\u0026gt; == ^tenant())\u003c/code\u003e to every create action that upserts on the primary key or on an \u003ccode\u003eall_tenants?\u003c/code\u003e identity, and do not combine it with \u003ccode\u003ereturn_skipped_upsert?\u003c/code\u003e. An upsert into another tenant\u0027s record then fails with \u003ccode\u003eAsh.Error.Changes.StaleRecord\u003c/code\u003e (or is skipped in a bulk create) and leaves that record unchanged. This does not help on the Mnesia data layer, which ignores upsert conditions in affected versions.\u003c/p\u003e\", \"base64\": false}, {\"type\": \"text/markdown\", \"value\": \"Add `upsert_condition expr(\u003ctenant attribute\u003e == ^tenant())` to every create action that upserts on the primary key or on an `all_tenants?` identity, and do not combine it with `return_skipped_upsert?`. An upsert into another tenant\u0027s record then fails with `Ash.Error.Changes.StaleRecord` (or is skipped in a bulk create) and leaves that record unchanged. This does not help on the Mnesia data layer, which ignores upsert conditions in affected versions.\", \"base64\": false}]}], \"dateAssigned\": \"2026-10-26T05:14:04.000Z\", \"descriptions\": [{\"lang\": \"en\", \"value\": \"Authorization Bypass Through User-Controlled Key vulnerability in ash-project ash allows a user of one tenant to read, overwrite and take over another tenant\u0027s records via an upserting create action.\\n\\nUnder attribute multitenancy, Ash.Actions.Create (lib/ash/actions/create/create.ex) and Ash.Actions.Create.Bulk (lib/ash/actions/create/bulk.ex) upserted on the primary key, or on an all_tenants? identity, without scoping the conflicting record to the request\u0027s tenant. A caller of a create action with upsert? true that accepts the primary key, supplying a record id from another tenant, updated that record\u0027s upsert fields and received all of its attributes in the result. With the default upsert fields the tenant attribute was written too, moving the record into the caller\u0027s tenant. Read and update policies do not run for upserts, and tenant-scoped create policies pass because the tenant is the caller\u0027s own.\\n\\nThis issue affects ash: from 1.22.0 before 3.37.2.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eAuthorization Bypass Through User-Controlled Key vulnerability in ash-project ash allows a user of one tenant to read, overwrite and take over another tenant\u0027s records via an upserting create action.\u003c/p\u003e\\n\u003cp\u003eUnder attribute multitenancy, \u003ccode\u003eAsh.Actions.Create\u003c/code\u003e (\u003ccode\u003elib/ash/actions/create/create.ex\u003c/code\u003e) and \u003ccode\u003eAsh.Actions.Create.Bulk\u003c/code\u003e (\u003ccode\u003elib/ash/actions/create/bulk.ex\u003c/code\u003e) upserted on the primary key, or on an \u003ccode\u003eall_tenants?\u003c/code\u003e identity, without scoping the conflicting record to the request\u0027s tenant. A caller of a create action with \u003ccode\u003eupsert? true\u003c/code\u003e that accepts the primary key, supplying a record id from another tenant, updated that record\u0027s upsert fields and received all of its attributes in the result. With the default upsert fields the tenant attribute was written too, moving the record into the caller\u0027s tenant. Read and update policies do not run for upserts, and tenant-scoped create policies pass because the tenant is the caller\u0027s own.\u003c/p\u003e\\n\u003cp\u003eThis issue affects ash: from 1.22.0 before 3.37.2.\u003c/p\u003e\", \"base64\": false}, {\"type\": \"text/markdown\", \"value\": \"Authorization Bypass Through User-Controlled Key vulnerability in ash-project ash allows a user of one tenant to read, overwrite and take over another tenant\u0027s records via an upserting create action.\\n\\nUnder attribute multitenancy, `Ash.Actions.Create` (`lib/ash/actions/create/create.ex`) and `Ash.Actions.Create.Bulk` (`lib/ash/actions/create/bulk.ex`) upserted on the primary key, or on an `all_tenants?` identity, without scoping the conflicting record to the request\u0027s tenant. A caller of a create action with `upsert? true` that accepts the primary key, supplying a record id from another tenant, updated that record\u0027s upsert fields and received all of its attributes in the result. With the default upsert fields the tenant attribute was written too, moving the record into the caller\u0027s tenant. Read and update policies do not run for upserts, and tenant-scoped create policies pass because the tenant is the caller\u0027s own.\\n\\nThis issue affects ash: from 1.22.0 before 3.37.2.\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-639\", \"description\": \"CWE-639 Authorization Bypass Through User-Controlled Key\"}]}], \"configurations\": [{\"lang\": \"en\", \"value\": \"Reachable when a resource uses attribute multitenancy and exposes to callers of one tenant a create action with upsert? true that either upserts on the primary key (no upsert_identity) and accepts it, or upserts on an all_tenants? identity, and the caller knows or can enumerate a key belonging to another tenant (for example a serial integer id, or an id from a shared link or export).\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eReachable when a resource uses attribute multitenancy and exposes to callers of one tenant a create action with \u003ccode\u003eupsert? true\u003c/code\u003e that either upserts on the primary key (no \u003ccode\u003eupsert_identity\u003c/code\u003e) and accepts it, or upserts on an \u003ccode\u003eall_tenants?\u003c/code\u003e identity, and the caller knows or can enumerate a key belonging to another tenant (for example a serial integer id, or an id from a shared link or export).\u003c/p\u003e\", \"base64\": false}, {\"type\": \"text/markdown\", \"value\": \"Reachable when a resource uses attribute multitenancy and exposes to callers of one tenant a create action with `upsert? true` that either upserts on the primary key (no `upsert_identity`) and accepts it, or upserts on an `all_tenants?` identity, and the caller knows or can enumerate a key belonging to another tenant (for example a serial integer id, or an id from a shared link or export).\", \"base64\": false}]}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"3.37.2\", \"versionStartIncluding\": \"1.22.0\"}], \"operator\": \"OR\"}], \"operator\": \"AND\"}], \"providerMetadata\": {\"orgId\": \"6b3ad84c-e1a6-4bf7-a703-f496b71e49db\", \"shortName\": \"EEF\", \"dateUpdated\": \"2026-10-26T07:20:07.186Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-96581\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-10-26T14:35:19.745Z\", \"dateReserved\": \"2026-10-25T17:30:02.206Z\", \"assignerOrgId\": \"6b3ad84c-e1a6-4bf7-a703-f496b71e49db\", \"datePublished\": \"2026-10-26T07:20:07.186Z\", \"assignerShortName\": \"EEF\"}",
      "dataType": "CVE_RECORD",
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}