Vulnerability · Published Oct 21, 2026 · Assigned by VulnCheck

CVE-2026-114118Vyper 0.3.4 through 0.5.0b1 create_from_blueprint Offset Validation Bypass via Unsigned Wraparound

Medium 4.8

In plain English

A medium-severity security flaw in vyper from vyperlang. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities).

Severity (CVSS 3.1)4.8Medium

Exploit odds (30 days)0.2%top 90.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
vyperlang	vyper	0.3.4 – through 0.5.0b1

Weakness: CWE-681 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

References

GitHub Security Advisory (GHSA-fxg7-4wqg-c8gh) vendor-advisory
VulnCheck Advisory: Vyper 0.3.4 through 0.5.0b1 create_from_blueprint Offset Validation Bypass via Unsigned Wraparound third-party-advisory