{"id":"EEF-CVE-2026-115635","summary":"AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set","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.","aliases":["CVE-2026-115635","GHSA-36hg-wwp2-fg8w"],"modified":"2026-10-25T20:11:06.333036314Z","published":"2026-10-25T19:48:43.829Z","database_specific":{"cwe_ids":["CWE-863"],"capec_ids":["CAPEC-1"],"cpe_ids":["cpe:2.3:a:ash-project:ash_postgres:*:*:*:*:*:*:*:*"]},"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"}],"affected":[{"package":{"name":"ash_postgres","ecosystem":"Hex","purl":"pkg:hex/ash_postgres"},"ranges":[{"type":"SEMVER","events":[{"introduced":"2.6.22"},{"fixed":"2.15.2"}]}],"versions":["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","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"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-115635.json"}},{"ranges":[{"type":"GIT","repo":"https://github.com/ash-project/ash_postgres","events":[{"introduced":"af0903f1380468bbe1b61fe65acb33772b5e24a5"},{"fixed":"8aa81220c401cae412d21078d11b3519ea25d3a9"}]}],"versions":["v2.15.1","v2.15.0","v2.14.5","v2.14.4","v2.14.3","v2.14.2","v2.14.1","v2.14.0","v2.13.1","v2.13.0","v2.12.0","v2.11.0","v2.10.0","v2.9.1","v2.9.0","v2.8.0","v2.7.0","v2.6.32","v2.6.31","v2.6.30","v2.6.29","v2.6.28","v2.6.27","v2.6.26","v2.6.25","v2.6.24","v2.6.23","v2.6.22"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-115635.json"}}],"schema_version":"1.9.0","severity":[{"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"}],"credits":[{"name":"Will Townsend","type":"FINDER"},{"name":"Will Townsend","type":"REPORTER"},{"name":"Zach Daniel / Ash Project","type":"REMEDIATION_DEVELOPER"}]}