CVE-2026-115635
AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set
- State
- Published
- Severity
- 6.0 Medium
- Published
- Oct 25, 2026
- Updated
- Oct 26, 2026
- Reserved
- Oct 23, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.0 Medium | 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 | EEF |
Weaknesses
- CWE-863 Incorrect Authorization
Affected Products
| Product | Versions |
|---|---|
ash_postgresash-project |
|
ash_postgresash-project |
|
References
- `Ash.bulk_create` with `return_skipped_upsert?: true` in AshPostgres returns another tenant's record for a skipped upsertvendor-advisoryrelated
- EEF CNA record for CVE-2026-115635related
- OSV record EEF-CVE-2026-115635related
- Introducing commit af0903f in ash-project/ash_postgresrelated
- Fix commit 8aa8122 in ash-project/ash_postgrespatch
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