VulnerabilityDeferred

CVE-2026-82732

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.

MEDIUM 6.3EPSS 0.39%

Does this matter?

Lower severity and a low EPSS score (0.39%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0: 6.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.39% probability · 32th percentile
CISA KEV: Not listed
Weakness: CWE-20
Source: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.