EEF-CVE-2026-82736 CVE-2026-82736 GHSA-gg9w-7593-hxg9
Ash.Type.CiString validates length and match constraints before case folding, allowing constraint bypass
- Severity
- 0.0 / 10
- Unknown · CVSS 4.0
- Exploit chance (EPSS)
- 0.18%
- Chance of exploitation in the next 30 days. Higher than 7.57% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-180 Incorrect Behavior Order: Validate Before Canonicalize
- Fix
3.32.2- Upgrade ash to this version or later
Description
Summary
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 versions
Hex
| Package | Vulnerable | Fixed in |
|---|---|---|
| ash | >= 1.29.0-rc0, < 3.32.2 |
3.32.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
ash Hex → 3.32.2
- mix
{:ash, "~> 3.32.2"} # then: mix deps.update ash
Severity breakdown
CVSS 4.0 0.0
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
- Attack vector
- Local
- Attack complexity
- Low
- Attack requirements
- Present
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- Low
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
Weakness
CWE-180: Incorrect Behavior Order: Validate Before Canonicalize
The product validates input before it is canonicalized, which prevents the product from detecting data that becomes invalid after the canonicalization step.
How to prevent it
- Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
References
Advisories
Fixes and patches
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| EEF-CVE-2026-96581 An upsert on the primary key in Ash ignores attribute multitenancy, so one tenant can read, overwrite and take over another tenant's records | Not rated yet | Also affects ash |
| EEF-CVE-2026-114214 Loading a through relationship with a limit of 1 in Ash ignores the through path and returns unrelated destination records | Not rated yet | Also affects ash |
| EEF-CVE-2026-101028 Ash.count, Ash.exists and Ash.aggregate skip related resources' read policies in filters and sorts | Not rated yet | Also affects ash |
| EEF-CVE-2026-94201 Filtering an :atom attribute with unsafe_to_atom? can exhaust the BEAM atom table in Ash | Not rated yet | Also affects ash |
| EEF-CVE-2026-93477 Private action arguments can be set by user input on the bulk destroy and bulk update paths in Ash | Not rated yet | Also affects ash |
| EEF-CVE-2026-86338 Ash field policies do not filter-nil forbidden calculations and aggregates, enabling an information-disclosure oracle | Not rated yet | Also affects ash |
| EEF-CVE-2026-82752 Ash string length constraints count graphemes, so a combining-mark string of any size passes max_length | Not rated yet | Also affects ash |
| EEF-CVE-2026-82747 Ash.Policy.Authorizer returns records denied by a runtime read policy to any actor | Not rated yet | Also affects ash |
Credits: Jonatan Männchen / EEF, Peter Ullrich, Zach Daniel / Ash Project
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