CVE-2026-115635 AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-115635?
CVE-2026-115635 is a medium-severity vulnerability in ash-project ash_postgres, published on 25 Oct 2026.
Official 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.
Weakness: CWE-863
Which versions are affected by CVE-2026-115635?
1 open source package ship an affected version, including ash_postgres.
| Package | Affected | Fixed in |
|---|---|---|
ash_postgres Hex | From 2.6.22 | 2.15.2 |
How do I fix CVE-2026-115635?
Upgrade ash_postgres to 2.15.2 or later.
Is CVE-2026-115635 being exploited?
There is no known exploitation of CVE-2026-115635 in the wild and no public exploit code.
Sources
Also known as EEF-CVE-2026-115635, GHSA-36hg-wwp2-fg8w.