# CVE-2026-4931: CVE-2026-4931

> Attackers can exploit unsafe downcasting in Marginal v1 smart contracts to settle large debts for negligible cost, impacting financial integrity.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Apr 2026
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-x4xq-7w28-q486

## What is CVE-2026-4931?

CVE-2026-4931 is a medium-severity vulnerability in Marginal Smart Contract, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Smart contract Marginal v1 performs unsafe downcast, allowing attackers to settle a large debt position for a negligible asset cost.

Weakness: CWE-681 (Incorrect Conversion between Numeric Types)

## Which versions are affected by CVE-2026-4931?

It affects 1 product.


Products: Marginal V1-Core.

## How do I fix CVE-2026-4931?

No fix has been published for CVE-2026-4931 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-4931 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4931 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4931 and fix it if it is affected.

What it is: CVE-2026-4931 is a medium-severity vulnerability in Marginal Smart Contract, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4931 exists.

Affected product: Marginal Smart Contract. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-4931/ (Markdown: https://insights.sbomify.com/CVE-2026-4931/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4931
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4931
- OSV: https://osv.dev/vulnerability/CVE-2026-4931

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-4931/
Summaries are generated and may contain mistakes; the official description above is the record.