CVE-2026-82740: Ash.Type ignores outer array constraints on nested {:array, {:array, type}} inputs

Severity: low (CVSS 2.1 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-01 · updated 2026-09-01
Weakness: CWE-20

Description

Improper Input Validation vulnerability in ash-project ash fails to enforce the outer array constraints on a doubly-nested {:array, {:array, type}} attribute, letting invalid input pass validation. Ash.Type.apply_constraints/3 (lib/ash/type/type.ex) handled the {:array, {:array, type}} case by mapping only the inner {:array, type} constraints over each element, so constraints declared on the outer array (such as min_length, max_length, and nil_items?) were never applied. An attacker could submit an outer list that violates those constraints (too many elements, or nil entries where disallowed) and have it accepted and persisted. The fix enforces the outer array constraints and adds explicit handling for nil and non-list inputs. This issue affects ash: from 2.16.1 before 3.32.2.

Affected products

ash-project ash: from 2.16.1 before 3.32.2 — fixed in 3.32.2

How to fix

Upgrade to a fixed version: ash-project ash 3.32.2. Check the vendor advisory for mitigations.

References

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