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Medium

AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set

Type: advisorySources: OSV

Incorrect Authorization vulnerability in ash-project ash_postgres allows a user to read another tenant's record through a skipped upsert. When 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. This issue affects ash_postgres: from 2.6.22 before 2.15.2.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-115635
Confirmed fixed CVEs
Not specified
Updated in this feed
5 Nov 2026, 16:53 UTC · Revision 1

Source evidence

AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set

core-osv · Original source

Published 25 Oct 2026, 19:48 UTC

Incorrect Authorization vulnerability in ash-project ash_postgres allows a user to read another tenant's record through a skipped upsert. When 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. This issue affects ash_postgres: from 2.6.22 before 2.15.2.

osv:CVE-2026-115635
Complete source record
{
  "id": "32070bee30c8b3761ee1e45e32160c9c00af83b2da67bc94e72545d7d46efd60",
  "url": "https://osv.dev/vulnerability/CVE-2026-115635",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set",
    "summary": "Incorrect Authorization vulnerability in ash-project ash_postgres allows a user to read another tenant's record through a skipped upsert. When 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. This issue affects ash_postgres: from 2.6.22 before 2.15.2.",
    "evidence": "osv:CVE-2026-115635",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-115635",
      "aliases": [
        "CVE-2026-115635",
        "EEF-CVE-2026-115635",
        "GHSA-36hg-wwp2-fg8w"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "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"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/ash-project/ash",
              "type": "GIT",
              "events": [
                {
                  "introduced": "6f6e820b21e3f84b85422c24e21bf7f30d548305"
                },
                {
                  "fixed": "4c46f5fa4631d569240eda88cffdbc9cb47b3d22"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "2.6.22"
                      },
                      {
                        "fixed": "2.15.2"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "2.6.22"
                      },
                      {
                        "fixed": "2.15.2"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            },
            {
              "repo": "https://github.com/ash-project/ash_postgres",
              "type": "GIT",
              "events": [
                {
                  "introduced": "af0903f1380468bbe1b61fe65acb33772b5e24a5"
                },
                {
                  "fixed": "8aa81220c401cae412d21078d11b3519ea25d3a9"
                },
                {
                  "fixed": "af0903f1380468bbe1b61fe65acb33772b5e24a5"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "af0903f1380468bbe1b61fe65acb33772b5e24a5"
                      },
                      {
                        "fixed": "8aa81220c401cae412d21078d11b3519ea25d3a9"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "fixed": "af0903f1380468bbe1b61fe65acb33772b5e24a5"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "8aa81220c401cae412d21078d11b3519ea25d3a9"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.15.1",
            "v2.15.0",
            "v2.14.21",
            "v2.14.20",
            "v2.14.19",
            "v2.14.18",
            "v2.14.17",
            "v2.14.16",
            "v2.14.15",
            "v2.14.14",
            "v2.14.13",
            "v2.14.12",
            "v2.14.11",
            "v2.14.10",
            "v2.14.9",
            "v2.14.8",
            "v2.14.7",
            "v2.14.6",
            "v2.14.5",
            "v2.14.4",
            "v2.14.3",
            "v2.14.2",
            "v2.14.1",
            "v2.14.0",
            "v2.13.4",
            "v2.13.3",
            "v2.13.2",
            "v2.13.1",
            "v2.13.0",
            "v2.12.1",
            "v2.12.0",
            "v2.11.11",
            "v2.11.10",
            "v2.11.9",
            "v2.11.8",
            "v2.11.7",
            "v2.11.6",
            "v2.11.5",
            "v2.11.4",
            "v2.11.3",
            "v2.11.2",
            "v2.11.1",
            "v2.11.0",
            "v2.11.0-rc.3",
            "v2.11.0-rc.2",
            "v2.11.0-rc.1",
            "v2.11.0-rc.0",
            "v2.10.2",
            "v2.10.1",
            "v2.10.0",
            "v2.9.29",
            "v2.9.28",
            "v2.9.27",
            "v2.9.26",
            "v2.9.25",
            "v2.9.24",
            "v2.9.23",
            "v2.9.22",
            "v2.9.21",
            "v2.9.20",
            "v2.9.19",
            "v2.9.18",
            "v2.9.17",
            "v2.9.16",
            "v2.9.15",
            "v2.9.14",
            "v2.9.13",
            "v2.9.12",
            "v2.9.11",
            "v2.9.10",
            "v2.9.9",
            "v2.9.8",
            "v2.9.7",
            "v2.9.6",
            "v2.9.5",
            "v2.9.4",
            "v2.9.3",
            "v2.9.2",
            "v2.9.1",
            "v2.9.0",
            "v2.8.1",
            "v2.8.0",
            "v2.7.1",
            "v2.7.0",
            "v2.6.31",
            "v2.6.30",
            "v2.6.29",
            "v2.6.27",
            "v2.6.26",
            "v2.6.25",
            "v2.6.24",
            "v2.6.23",
            "v2.6.22"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-115635.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:44.489505796Z",
      "provider": "osv",
      "references": [
        "https://cna.erlef.org/cves/CVE-2026-115635.html",
        "https://github.com",
        "https://osv.dev/vulnerability/EEF-CVE-2026-115635",
        "https://repo.hex.pm",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/115xxx/CVE-2026-115635.json",
        "https://github.com/ash-project/ash/security/advisories/GHSA-36hg-wwp2-fg8w",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-115635",
        "https://github.com/ash-project/ash_postgres/commit/8aa81220c401cae412d21078d11b3519ea25d3a9",
        "https://github.com/ash-project/ash_postgres/commit/af0903f1380468bbe1b61fe65acb33772b5e24a5",
        "https://github.com/ash-project/ash_postgres"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-863"
        ],
        "cna_assigner": "EEF",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/115xxx/CVE-2026-115635.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-115635",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 512474,
  "published_at": "2026-10-25T19:48:43.829+00:00"
}