# 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.

- **Severity:** Medium 5.9 (`CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Aug 2026
- **Updated:** 31 Aug 2026
- **Also known as:** EEF-CVE-2026-78038, GHSA-gj9p-x393-rf9h

## 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 (Improperly Controlled Modification of Dynamically-Determined Object Attributes)

## Which versions are affected by CVE-2026-78038?

1 open source package ship an affected version, including ash_oban.


| Package | Ecosystem | 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.

## Is CVE-2026-78038 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-78038 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-78038 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-78038 exists.

Affected packages and fixed versions:
- ash_oban (Hex): affected from 0.2.5; fixed in 0.8.14

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-78038/ (Markdown: https://insights.sbomify.com/CVE-2026-78038/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-78038
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-78038
- OSV: https://osv.dev/vulnerability/CVE-2026-78038

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-78038/
Summaries are generated and may contain mistakes; the official description above is the record.