Am I affected?
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.
Weaknesses & attack patterns
Weakness
CWE-180
·
Incorrect Behavior Order: Validate Before Canonicalize
in catalog →
MITRE ↗
Attack patterns
CAPEC-267
·
Leverage Alternate Encoding
MITRE ↗
Affected — Hex / ash Hex.pm ↗ Repository ↗
modules · source files · routines
Affected — GitHub / ash-project/ash Repository ↗
modules · source files · routines
References
GHSA-gg9w-7593-hxg9 ↗
vendor-advisory
EEF-CVE-2026-82736 ↗
related
Credits
CVSS breakdown
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N