{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-115635",
        "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "state": "PUBLISHED",
        "assignerShortName": "EEF",
        "dateReserved": "2026-10-23T13:00:02.145Z",
        "datePublished": "2026-10-25T19:48:43.829Z",
        "dateUpdated": "2026-10-25T19:48:43.829Z"
    },
    "containers": {
        "cna": {
            "affected": [
                {
                    "collectionURL": "https://repo.hex.pm",
                    "cpes": [
                        "cpe:2.3:a:ash-project:ash_postgres:*:*:*:*:*:*:*:*"
                    ],
                    "defaultStatus": "unaffected",
                    "modules": [
                        "'Elixir.AshPostgres.DataLayer'"
                    ],
                    "packageName": "ash_postgres",
                    "packageURL": "pkg:hex/ash_postgres",
                    "product": "ash_postgres",
                    "programFiles": [
                        "lib/data_layer.ex"
                    ],
                    "programRoutines": [
                        {
                            "name": "'Elixir.AshPostgres.DataLayer':do_bulk_create/3"
                        },
                        {
                            "name": "'Elixir.AshPostgres.DataLayer':upsert/4"
                        },
                        {
                            "name": "'Elixir.AshPostgres.DataLayer':bulk_create/3"
                        }
                    ],
                    "repo": "https://github.com/ash-project/ash_postgres",
                    "vendor": "ash-project",
                    "versions": [
                        {
                            "lessThan": "2.15.2",
                            "status": "affected",
                            "version": "2.6.22",
                            "versionType": "semver"
                        }
                    ]
                },
                {
                    "collectionURL": "https://github.com",
                    "cpes": [
                        "cpe:2.3:a:ash-project:ash_postgres:*:*:*:*:*:*:*:*"
                    ],
                    "defaultStatus": "unaffected",
                    "modules": [
                        "'Elixir.AshPostgres.DataLayer'"
                    ],
                    "packageName": "ash-project/ash_postgres",
                    "packageURL": "pkg:github/ash-project/ash_postgres",
                    "product": "ash_postgres",
                    "programFiles": [
                        "lib/data_layer.ex"
                    ],
                    "programRoutines": [
                        {
                            "name": "'Elixir.AshPostgres.DataLayer':do_bulk_create/3"
                        },
                        {
                            "name": "'Elixir.AshPostgres.DataLayer':upsert/4"
                        },
                        {
                            "name": "'Elixir.AshPostgres.DataLayer':bulk_create/3"
                        }
                    ],
                    "repo": "https://github.com/ash-project/ash_postgres",
                    "vendor": "ash-project",
                    "versions": [
                        {
                            "lessThan": "8aa81220c401cae412d21078d11b3519ea25d3a9",
                            "status": "affected",
                            "version": "af0903f1380468bbe1b61fe65acb33772b5e24a5",
                            "versionType": "git"
                        }
                    ]
                }
            ],
            "configurations": [
                {
                    "lang": "en",
                    "supportingMedia": [
                        {
                            "base64": false,
                            "type": "text/html",
                            "value": "<p>Reachable when a resource uses attribute multitenancy, an action performs upserts with <code>return_skipped_upsert?: true</code>, and a caller can supply identity values that another tenant also uses.</p>"
                        },
                        {
                            "base64": false,
                            "type": "text/markdown",
                            "value": "Reachable when a resource uses attribute multitenancy, an action performs upserts with `return_skipped_upsert?: true`, and a caller can supply identity values that another tenant also uses."
                        }
                    ],
                    "value": "Reachable when a resource uses attribute multitenancy, an action performs upserts with return_skipped_upsert?: true, and a caller can supply identity values that another tenant also uses."
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "cpeMatch": [
                                {
                                    "criteria": "cpe:2.3:a:ash-project:ash_postgres:*:*:*:*:*:*:*:*",
                                    "versionEndExcluding": "2.15.2",
                                    "versionStartIncluding": "2.6.22",
                                    "vulnerable": true
                                }
                            ],
                            "negate": false,
                            "operator": "OR"
                        }
                    ],
                    "operator": "AND"
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "type": "finder",
                    "value": "Will Townsend"
                },
                {
                    "lang": "en",
                    "type": "reporter",
                    "value": "Will Townsend"
                },
                {
                    "lang": "en",
                    "type": "remediation developer",
                    "value": "Zach Daniel / Ash Project"
                }
            ],
            "dateAssigned": "2026-10-25T17:27:42.000Z",
            "descriptions": [
                {
                    "lang": "en",
                    "supportingMedia": [
                        {
                            "base64": false,
                            "type": "text/html",
                            "value": "<p>Incorrect Authorization vulnerability in ash-project ash_postgres allows a user to read another tenant's record through a skipped upsert.</p>\n<p>When <code>Ash.bulk_create/4</code> or a single create runs as an upsert with <code>return_skipped_upsert?: true</code> and the upsert is skipped (for example because its <code>upsert_condition</code> does not hold), <code>AshPostgres.DataLayer</code> reads the existing row back by the upsert identity in <code>do_bulk_create/3</code> and <code>upsert/4</code>. That lookup did not apply the resource's attribute multitenancy, so on a resource using <code>strategy :attribute</code> it could match and return the row of another tenant with the same identity values, exposing its fields to the caller.</p>\n<p>This issue affects ash_postgres: from 2.6.22 before 2.15.2.</p>"
                        },
                        {
                            "base64": false,
                            "type": "text/markdown",
                            "value": "Incorrect Authorization vulnerability in ash-project ash_postgres allows a user to read another tenant's record through a skipped upsert.\n\nWhen `Ash.bulk_create/4` or a single create runs as an upsert with `return_skipped_upsert?: true` and the upsert is skipped (for example because its `upsert_condition` does not hold), `AshPostgres.DataLayer` reads the existing row back by the upsert identity in `do_bulk_create/3` and `upsert/4`. That lookup did not apply the resource's attribute multitenancy, so on a resource using `strategy :attribute` it could match and return the row of another tenant with the same identity values, exposing its fields to the caller.\n\nThis issue affects ash_postgres: from 2.6.22 before 2.15.2."
                        }
                    ],
                    "value": "Incorrect Authorization vulnerability in ash-project ash_postgres allows a user to read another tenant's record through a skipped upsert.\n\nWhen Ash.bulk_create/4 or a single create runs as an upsert with return_skipped_upsert?: true and the upsert is skipped (for example because its upsert_condition does not hold), AshPostgres.DataLayer reads the existing row back by the upsert identity in do_bulk_create/3 and upsert/4. That lookup did not apply the resource's attribute multitenancy, so on a resource using strategy :attribute it could match and return the row of another tenant with the same identity values, exposing its fields to the caller.\n\nThis issue affects ash_postgres: from 2.6.22 before 2.15.2."
                }
            ],
            "impacts": [
                {
                    "capecId": "CAPEC-1",
                    "descriptions": [
                        {
                            "lang": "en",
                            "supportingMedia": [
                                {
                                    "base64": false,
                                    "type": "text/html",
                                    "value": "<p>A user of one tenant whose upsert is skipped receives another tenant's record with the same identity values.</p>"
                                },
                                {
                                    "base64": false,
                                    "type": "text/markdown",
                                    "value": "A user of one tenant whose upsert is skipped receives another tenant's record with the same identity values."
                                }
                            ],
                            "value": "A user of one tenant whose upsert is skipped receives another tenant's record with the same identity values."
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "Automatable": "NOT_DEFINED",
                        "Recovery": "NOT_DEFINED",
                        "Safety": "NOT_DEFINED",
                        "attackComplexity": "LOW",
                        "attackRequirements": "PRESENT",
                        "attackVector": "NETWORK",
                        "baseScore": 6,
                        "baseSeverity": "MEDIUM",
                        "privilegesRequired": "LOW",
                        "providerUrgency": "NOT_DEFINED",
                        "subAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "userInteraction": "NONE",
                        "valueDensity": "NOT_DEFINED",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
                        "version": "4.0",
                        "vulnAvailabilityImpact": "NONE",
                        "vulnConfidentialityImpact": "HIGH",
                        "vulnIntegrityImpact": "NONE",
                        "vulnerabilityResponseEffort": "NOT_DEFINED"
                    },
                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
                        }
                    ]
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-863",
                            "description": "CWE-863 Incorrect Authorization",
                            "lang": "en",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
                "shortName": "EEF",
                "dateUpdated": "2026-10-25T19:48:43.829Z"
            },
            "references": [
                {
                    "name": "`Ash.bulk_create` with `return_skipped_upsert?: true` in AshPostgres returns another tenant's record for a skipped upsert",
                    "tags": [
                        "vendor-advisory",
                        "related"
                    ],
                    "url": "https://github.com/ash-project/ash/security/advisories/GHSA-36hg-wwp2-fg8w"
                },
                {
                    "name": "EEF CNA record for CVE-2026-115635",
                    "tags": [
                        "related"
                    ],
                    "url": "https://cna.erlef.org/cves/CVE-2026-115635.html"
                },
                {
                    "name": "OSV record EEF-CVE-2026-115635",
                    "tags": [
                        "related"
                    ],
                    "url": "https://osv.dev/vulnerability/EEF-CVE-2026-115635"
                },
                {
                    "name": "Introducing commit af0903f in ash-project/ash_postgres",
                    "tags": [
                        "related"
                    ],
                    "url": "https://github.com/ash-project/ash_postgres/commit/af0903f1380468bbe1b61fe65acb33772b5e24a5"
                },
                {
                    "name": "Fix commit 8aa8122 in ash-project/ash_postgres",
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/ash-project/ash_postgres/commit/8aa81220c401cae412d21078d11b3519ea25d3a9"
                }
            ],
            "source": {
                "discovery": "EXTERNAL"
            },
            "title": "AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set"
        }
    }
}