CVE-2026-82736
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.
Does this matter?
Lower severity and a low EPSS score (0.14%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 2.1 LOWCVSS:4.0/AV:L/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
- 0.14% probability · 4th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-180
- Source
- 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
References
- https://cna.erlef.org/cves/CVE-2026-82736.html
- https://github.com/ash-project/ash/commit/d8320b0127c8ef453679d70e5dd23a9506951d21
- https://github.com/ash-project/ash/security/advisories/GHSA-gg9w-7593-hxg9
- https://osv.dev/vulnerability/EEF-CVE-2026-82736
- https://github.com/ash-project/ash/security/advisories/GHSA-gg9w-7593-hxg9
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.