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Low · 2.1 CVE-2026-82736 EEF-CVE-2026-82736EUVD-2026-68963GHSA-gg9w-7593-hxg9

Ash.Type.CiString validates length and match constraints before case folding, allowing constraint bypass

Published Sep 1, 2026 · Updated Sep 1, 2026 · Assigned by EEF

Description

Incorrect Behavior Order: Validate Before Canonicalize vulnerability in ash-project ash lets an attacker store a case-insensitive string value that violates its length or match constraints.

Ash.Type.CiString.apply_constraints/2 (lib/ash/type/ci_string.ex) validated the max_length, min_length, and match constraints against the value as submitted, while the type case-folds the string (per its casing) for storage and comparison. Because validation ran before folding, an attacker can submit a value whose folded form breaks a constraint but whose original form passes: for example, against a match pattern requiring uppercase, an uppercase value that is stored lowercased persists a value the pattern rejects. The fix case-folds the value at the start of apply_constraints/2, so the constraints are checked against the form that is actually stored.

This issue affects ash: from 1.29.0-rc0 before 3.32.2.

Affected products

VendorProductAffectedFixed
ash-project ash 1.29.0-rc0 – < 3.32.2 3.32.2

Affected packages

EcosystemPackageAffectedFixedRecord
Hex ash >= 1.29.0-rc0, < 3.32.2 3.32.2 EEF-CVE-2026-82736

References