Vyper 0.3.4 through 0.5.0b1 create_from_blueprint Offset Validation Bypass via Unsigned Wraparound

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

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.

Source published

21 Oct 2026 00:37:15 UTC

Source modified

27 Oct 2026 21:58:34 UTC

Observed here

27 Oct 2026 23:45:55 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

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CVSS 4.0 · 6.3 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

CVSS 3.1 · 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L