# CVE-2026-97853: Unbounded allocation in decimal Decimal.round/3 driven by the places argument enables DoS

> Attackers can cause denial of service by supplying large decimal place arguments, exhausting memory in applications using the Elixir decimal library.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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:** 10 Oct 2026
- **Updated:** 15 Oct 2026
- **Also known as:** EEF-CVE-2026-97853, GHSA-6c27-994x-c52f

## What is CVE-2026-97853?

CVE-2026-97853 is a medium-severity denial of service vulnerability in ericmj decimal, published on 10 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Memory Allocation with Excessive Size Value vulnerability in ericmj decimal allows Denial of Service.

Decimal.round/3 builds the full result for the requested number of decimal places before the context precision (34 digits by default) is applied, so its cost grows with the places argument instead of with the size of the result. For positive places it appends places zero digits to the coefficient as a charlist before converting it to an integer, and for negative places it builds a charlist of -places zero digits. A single call such as Decimal.round(Decimal.new("1.5"), -50_000_000) allocates about 5.5 GB of memory, which can exhaust available memory and get the BEAM VM killed. The oldest releases instead loop once per decimal place, consuming CPU in proportion to places.

Any application that passes a user-supplied number of decimal places or scale to Decimal.round/2 or Decimal.round/3 without bounding it is exposed. The input limits added for CVE-2026-32686 do not cover the places argument.

This issue affects decimal: from 0.1.0 before 3.1.2.

Weakness: CWE-789 (Memory Allocation with Excessive Size Value)

## Which versions are affected by CVE-2026-97853?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `decimal` | Hex | From 0.1.0 | 3.1.2 |

## How do I fix CVE-2026-97853?

Upgrade decimal to 3.1.2 or later.

## Is CVE-2026-97853 being exploited?

There is no known exploitation of CVE-2026-97853 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97853 and fix it if it is affected.

What it is: CVE-2026-97853 is a medium-severity denial of service vulnerability in ericmj decimal, published on 10 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-97853 in the wild and no public exploit code.

Affected packages and fixed versions:
- decimal (Hex): affected from 0.1.0; fixed in 3.1.2

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-2026-97853/ (Markdown: https://insights.sbomify.com/CVE-2026-97853/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97853
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97853
- OSV: https://osv.dev/vulnerability/CVE-2026-97853

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97853/
Summaries are generated and may contain mistakes; the official description above is the record.