---
id: CVE-2026-114118
title: >-
  Vyper 0.3.4 through 0.5.0b1 create_from_blueprint Offset Validation Bypass via
  Unsigned Wraparound
summary: >-
  Vyper 0.3.4 through 0.5.0b1 computes the remaining blueprint size in
  create_from_blueprint by uint256 subtraction without first checking that
  code_offset is below the blueprint's code size, so a huge offset wraps to a
  small positive valu…
severity: medium
cvss: 4.8
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L'
cvssSource: cna
cwe:
  - CWE-681
vendor: vyperlang
product: vyper
affected:
  - vyper >= 0.3.4 <= 0.5.0b1
published: '2026-10-21'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T00:37:15.454Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-114118'
references:
  - url: 'https://github.com/vyperlang/vyper/security/advisories/GHSA-fxg7-4wqg-c8gh'
    label: GitHub Security Advisory (GHSA-fxg7-4wqg-c8gh)
  - url: >-
      https://www.vulncheck.com/advisories/vyper-0.3.4-through-0.5-0b1-create-from-blueprint-offset-validation-bypass-via-unsigned-wraparound
    label: >-
      VulnCheck Advisory: Vyper 0.3.4 through 0.5.0b1 create_from_blueprint
      Offset Validation Bypass via Unsigned Wraparound
tags:
  - cve.org
ingestedAt: '2026-10-21T01:37:08.008Z'
---

## Overview

Vyper 0.3.4 through 0.5.0b1 computes the remaining blueprint size in create_from_blueprint by uint256 subtraction without first checking that code_offset is below the blueprint's code size, so a huge offset wraps to a small positive value. An attacker controlling code_offset can make a factory deploy contracts with no runtime code, potentially trapping ETH and tokens.

## Affected

- `vyper >= 0.3.4 <= 0.5.0b1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.