# CVE-2026-82732: Declared argument constraints not enforced on AshTypescript typed controller routes

> Attackers bypass declared argument constraints in AshTypescript routes, potentially escalating privileges or modifying data by submitting invalid values.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Sep 2026
- **Updated:** 1 Sep 2026
- **Also known as:** EEF-CVE-2026-82732, GHSA-f7fq-hwq6-jhvv

## What is CVE-2026-82732?

CVE-2026-82732 is a medium-severity missing authorization vulnerability in ash-project ash_typescript, published on 1 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper Input Validation vulnerability in ash-project ash_typescript allows a remote attacker to submit argument values outside a declared allowlist or bound on typed-controller routes.

AshTypescript.TypedController.RequestHandler in lib/ash_typescript/typed_controller/request_handler.ex calls Ash.Type.cast_input/3 and treats an {:ok, cast} result as fully validated. In Ash these are separate steps: cast_input/3 only coerces the term, while every constraint declared on the argument is applied by Ash.Type.apply_constraints/3, which this path never calls. Constraints such as one_of, max_length, min and max, and match are therefore inert, so a value outside a declared allowlist is accepted and passed to the route handler. Codegen renders the same constraints into the generated TypeScript types, so an allowlist appears enforced to a TypeScript caller while any other HTTP client ignores it. Empty-string to nil normalization also lives in apply_constraints, so the allow_nil?: false check accepts "" for a required argument.

Where a constraint gates a role, a status, or a sort direction, this becomes a privilege or state-machine bypass.

This issue affects ash_typescript: from 0.15.0 before 0.18.0.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-82732?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ash_typescript` | Hex | From 0.15.0 | 0.18.0 |

## How do I fix CVE-2026-82732?

Upgrade ash_typescript to 0.18.0 or later.

## Is CVE-2026-82732 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82732 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82732 and fix it if it is affected.

What it is: CVE-2026-82732 is a medium-severity missing authorization vulnerability in ash-project ash_typescript, published on 1 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82732 exists.

Affected packages and fixed versions:
- ash_typescript (Hex): affected from 0.15.0; fixed in 0.18.0

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-2026-82732/ (Markdown: https://insights.sbomify.com/CVE-2026-82732/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82732
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82732
- OSV: https://osv.dev/vulnerability/CVE-2026-82732

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-82732/
Summaries are generated and may contain mistakes; the official description above is the record.