# CVE-2026-82734: Non-finite Infinity/NaN decimal values bypass bounds constraints in Ash.Type.Decimal

> Attackers can inject non-finite decimal values to bypass bounds checks, causing application crashes or data persistence failures in the Ash framework.

- **Severity:** Low 2.1 (`CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Sep 2026
- **Updated:** 1 Sep 2026
- **Also known as:** EEF-CVE-2026-82734, GHSA-mvvh-q33h-q62v

## What is CVE-2026-82734?

CVE-2026-82734 is a low-severity vulnerability in ash-project ash, published on 1 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Improper Validation of Specified Quantity in Input vulnerability in ash-project ash allows an attacker to submit a non-finite decimal value that bypasses numeric bounds constraints or fails later operations on the value.

Ash.Type.Decimal cast input through Ecto's decimal cast in cast_input/2 and cast_stored/2 (lib/ash/type/decimal.ex) without checking that the resulting value is finite. Elixir's Decimal represents Infinity and NaN as valid structs, so a value such as "Infinity" or "NaN" passed casting and was persisted. Because NaN compares as false against every bound, min and max constraints do not reject it, and the stored special value later raises when used in Decimal arithmetic or is refused by the data layer, failing subsequent requests. The fix rejects any non-finite Decimal during casting.

This issue affects ash: from 1.28.0 before 3.32.2.

Weakness: CWE-1284 (Improper Validation of Specified Quantity in Input)

## Which versions are affected by CVE-2026-82734?

1 open source package ship an affected version, including ash.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ash` | Hex | From 1.28.0 | 3.32.2 |

## How do I fix CVE-2026-82734?

Upgrade ash to 3.32.2 or later.

## Is CVE-2026-82734 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82734 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82734 and fix it if it is affected.

What it is: CVE-2026-82734 is a low-severity vulnerability in ash-project ash, published on 1 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82734 exists.

Affected packages and fixed versions:
- ash (Hex): affected from 1.28.0; fixed in 3.32.2

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-82734/ (Markdown: https://insights.sbomify.com/CVE-2026-82734/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82734
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82734
- OSV: https://osv.dev/vulnerability/CVE-2026-82734

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-82734/
Summaries are generated and may contain mistakes; the official description above is the record.