{"id":"CVE-2026-115635","state":"PUBLISHED","title":"AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set","description":"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.","publishedAt":"2026-10-25T19:48:43.829Z","updatedAt":"2026-10-26T14:35:21.261Z","severity":{"score":6,"label":"Medium","version":"4.0","vector":"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","source":"EEF"},"assigner":"EEF","products":["ash-project ash_postgres"],"affected":[{"vendor":"ash-project","product":"ash_postgres","packageName":"ash_postgres","packageURL":"pkg:hex/ash_postgres","defaultStatus":"unaffected","versions":[{"version":"2.6.22","status":"affected","lessThan":"2.15.2","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash_postgres:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshPostgres.DataLayer'"],"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","product":"ash_postgres","packageName":"ash-project/ash_postgres","packageURL":"pkg:github/ash-project/ash_postgres","defaultStatus":"unaffected","versions":[{"version":"af0903f1380468bbe1b61fe65acb33772b5e24a5","status":"affected","lessThan":"8aa81220c401cae412d21078d11b3519ea25d3a9","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash_postgres:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshPostgres.DataLayer'"],"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"}],"references":["https://github.com/ash-project/ash/security/advisories/GHSA-36hg-wwp2-fg8w","https://cna.erlef.org/cves/CVE-2026-115635.html","https://osv.dev/vulnerability/EEF-CVE-2026-115635","https://github.com/ash-project/ash_postgres/commit/af0903f1380468bbe1b61fe65acb33772b5e24a5","https://github.com/ash-project/ash_postgres/commit/8aa81220c401cae412d21078d11b3519ea25d3a9"],"weaknesses":["CWE-863"],"ingestedAt":"2026-10-29T20:10:43.281Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/115xxx/CVE-2026-115635.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-115635","state":"PUBLISHED","datePublished":"2026-10-25T19:48:43.829Z","dateUpdated":"2026-10-26T14:35:21.261Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-10-23T13:00:02.145Z"},"containers":{"cna":{"title":"AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set","descriptions":[{"lang":"en","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."}],"affected":[{"vendor":"ash-project","product":"ash_postgres","packageName":"ash_postgres","packageURL":"pkg:hex/ash_postgres","defaultStatus":"unaffected","versions":[{"version":"2.6.22","status":"affected","lessThan":"2.15.2","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash_postgres:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshPostgres.DataLayer'"],"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","product":"ash_postgres","packageName":"ash-project/ash_postgres","packageURL":"pkg:github/ash-project/ash_postgres","defaultStatus":"unaffected","versions":[{"version":"af0903f1380468bbe1b61fe65acb33772b5e24a5","status":"affected","lessThan":"8aa81220c401cae412d21078d11b3519ea25d3a9","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash_postgres:*:*:*:*:*:*:*:*"],"modules":["'Elixir.AshPostgres.DataLayer'"],"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"}],"references":[{"url":"https://github.com/ash-project/ash/security/advisories/GHSA-36hg-wwp2-fg8w","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://cna.erlef.org/cves/CVE-2026-115635.html","name":"EEF CNA record for CVE-2026-115635","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-115635","name":"OSV record EEF-CVE-2026-115635","tags":["related"]},{"url":"https://github.com/ash-project/ash_postgres/commit/af0903f1380468bbe1b61fe65acb33772b5e24a5","name":"Introducing commit af0903f in ash-project/ash_postgres","tags":["related"]},{"url":"https://github.com/ash-project/ash_postgres/commit/8aa81220c401cae412d21078d11b3519ea25d3a9","name":"Fix commit 8aa8122 in 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