CVE-2026-82732

Declared argument constraints not enforced on AshTypescript typed controller routes

MEDIUM
6.3
CVSS Score
Published: September 1, 2026 at 02:09 AM UTC
Updated: September 1, 2026 at 09:31 PM UTC
1 product affected across 1 vendorAshTypescript

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Severity
MEDIUM6.3
Exploit prediction
EPSS 0.7%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

0.15.0 ≤ v < 0.18.00.15.0546a15e1a2d7dbf1df2d5a6ee4404bc3da87852e
Vendor states this is fixed in 21ab6f1229a4dccdb56bc37ed437d9672a0c4a4e (fixed)
Affected range stops below 0.18.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.3MEDIUMEEF
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-20

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