CVE-2026-82740 json
Ash.Type ignores outer array constraints on nested {:array, {:array, type}} inputs
published 2mo ago modified 2mo ago also EEF-CVE-2026-82740 , EUVD-2026-68945 , GHSA-v29m-p28g-w5fc
- cvss
- 2.1
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 7%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
Is CVE-2026-82740 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2mo ago
Exploit prediction
0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-11).
Exploits and checks
- github.com https://github.com/ash-project/ash/security/advisories/GHSA-v29m-p28g-w5fc referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 2.1 | 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 |
| CNA | 4.0 | 2.1 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| hex | ash | >=2.16.1, <3.32.2 |
3.32.2 |
Affected products
- ash-project ash
Classification
- Weakness
-
- CWE-20 Improper Input Validation
References
-
github.com
/ash-project/ash/commit/c85ccff7dc6e3b0b3e40ad788b0056b3b6bee5ce
patch
-
github.com
/ash-project/ash/security/advisories/GHSA-v29m-p28g-w5fc
vendor-advisory, related, exploit, advisory
-
cna.erlef.org
/cves/CVE-2026-82740.html
related, web
-
osv.dev
/vulnerability/EEF-CVE-2026-82740
related
-
hex.pm
/packages/ash
package
Sources
- CVE List CVE-2026-82740
- NVD CVE-2026-82740
- OSV EEF-CVE-2026-82740
- Maintainer advisory GHSA-v29m-p28g-w5fc
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of ash-project/ash published their own advisory on GitHub. Reviewed sources take precedence over it.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.