{"affected":[{"package":{"ecosystem":"Hex","name":"ash_postgres","purl":"pkg:hex/ash_postgres"},"ranges":[{"events":[{"introduced":"2.6.22"},{"fixed":"2.15.2"}],"type":"SEMVER"}],"versions":["2.6.22","2.6.23","2.6.24","2.6.25","2.6.26","2.6.27","2.6.28","2.6.29","2.6.30","2.6.31","2.6.32","2.7.0","2.8.0","2.9.0","2.9.1","2.10.0","2.11.0","2.12.0","2.13.0","2.13.1","2.14.0","2.14.1","2.14.2","2.14.3","2.14.4","2.14.5","2.15.0","2.15.1"]},{"ranges":[{"events":[{"introduced":"af0903f1380468bbe1b61fe65acb33772b5e24a5"},{"fixed":"8aa81220c401cae412d21078d11b3519ea25d3a9"}],"repo":"https://github.com/ash-project/ash_postgres","type":"GIT"}]}],"aliases":["GHSA-36hg-wwp2-fg8w","CVE-2026-115635"],"credits":[{"name":"Will Townsend","type":"FINDER"},{"name":"Will Townsend","type":"REPORTER"},{"name":"Zach Daniel / Ash Project","type":"REMEDIATION_DEVELOPER"}],"database_specific":{"capec_ids":["CAPEC-1"],"cpe_ids":["cpe:2.3:a:ash-project:ash_postgres:*:*:*:*:*:*:*:*"],"cwe_ids":["CWE-863"]},"details":"## Summary\n\nIncorrect 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.\n\n## Impact\n\nA user of one tenant whose upsert is skipped receives another tenant's record with the same identity values.\n\n## Configurations\n\nReachable 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.","id":"EEF-CVE-2026-115635","modified":"2026-10-25T19:48:44.274127Z","published":"2026-10-25T19:48:43.829Z","references":[{"type":"ADVISORY","url":"https://github.com/ash-project/ash/security/advisories/GHSA-36hg-wwp2-fg8w"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-115635.html"},{"type":"WEB","url":"https://github.com/ash-project/ash_postgres/commit/af0903f1380468bbe1b61fe65acb33772b5e24a5"},{"type":"FIX","url":"https://github.com/ash-project/ash_postgres/commit/8aa81220c401cae412d21078d11b3519ea25d3a9"},{"type":"PACKAGE","url":"https://hex.pm/packages/ash_postgres"}],"related":[],"schema_version":"1.7.3","severity":[{"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","type":"CVSS_V4"}],"summary":"AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set","upstream":[]}