# CVE-2026-114663: Vyper 0.4.0b1 through 0.5.0b1 Name Shadowing of Imported Constants and Default Arguments


- **Severity:** High 8.6 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 22 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** GHSA-2489-32vh-8rrc, GHSA-9r8w-599f-g6jq

## What is CVE-2026-114663?

CVE-2026-114663 is a high-severity vulnerability in vyperlang vyper, published on 22 Oct 2026. 

### Official description

Vyper 0.4.0b1 through 0.5.0b1 miscompiles unfoldable constants and omitted default arguments from imported modules, because parse_Name resolves their names in the using function's scope rather than at declaration. When a contract's parameter, local, or loop variable shares such a name, attacker-influenced input can replace the intended value, including out-of-range values for narrow types such as uint8, corrupting validation or accounting logic.

Weakness: CWE-706 (Use of Incorrectly-Resolved Name or Reference)

## Which versions are affected by CVE-2026-114663?


## How do I fix CVE-2026-114663?

No fix has been published for CVE-2026-114663 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-114663 being exploited?

There is no known exploitation of CVE-2026-114663 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-114663 and fix it if it is affected.

What it is: CVE-2026-114663 is a high-severity vulnerability in vyperlang vyper, published on 22 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-114663 in the wild and no public exploit code.

Affected product: vyperlang vyper. 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-2026-114663/ (Markdown: https://insights.sbomify.com/CVE-2026-114663/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-114663
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-114663
- OSV: https://osv.dev/vulnerability/CVE-2026-114663

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-114663/
Summaries are generated and may contain mistakes; the official description above is the record.