CVE-2026-78038 Job argument injection via :args overrides primary_key and tenant in AshOban
Attackers can bypass tenant isolation and authorization controls by injecting arguments into AshOban triggers, allowing unauthorized modification of records across tenants.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-78038?
CVE-2026-78038 is a medium-severity missing authorization vulnerability in ash-project ash_oban, published on 30 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Improperly Controlled Modification of Dynamically-Determined Object Attributes vulnerability in ash-project ash_oban allows a user whose input reaches the :args option of AshOban.build_trigger/3 to retarget an update or destroy trigger at another record, including across tenants.
build_trigger/3 builds the trusted job arguments with atom keys (:primary_key, :tenant, :action_arguments) and merges the caller's :args underneath so the trusted values win on collision. Because Oban job arguments round-trip through JSON, the caller's keys arrive as strings, so Map.merge sees no collision and both keys survive. When the job is persisted the JSON object is de-duplicated keeping the last (string) key, and the worker reads the caller's value. The documentation describes :args as unable to affect the action, so an application that forwards user input into it for uniqueness scoping is exposed to authorization bypass and tenant isolation breaks.
This issue affects ash_oban: from 0.2.5 before 0.8.14.
Weakness: CWE-915
Which versions are affected by CVE-2026-78038?
1 open source package ship an affected version, including ash_oban.
| Package | Affected | Fixed in |
|---|---|---|
ash_oban Hex | From 0.2.5 | 0.8.14 |
How do I fix CVE-2026-78038?
Upgrade ash_oban to 0.8.14 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-78038 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-78038 exists.
Sources
Also known as EEF-CVE-2026-78038, GHSA-gj9p-x393-rf9h.