High · CVSS 8.6CVE-2026-114663

Vyper 0.4.0b1 through 0.5.0b1 Name Shadowing of Imported Constants and Default ArgumentsCVE-2026-114663

Answer in brief

CVE-2026-114663 records a High severity (CVSS 8.6) vulnerability in Vyper 0.4.0b1 through 0.5.0b1 Name Shadowing of Imported Constants and Default Arguments. The current sources do not mark it as known exploited. The current feed maps vyperlang/vyper (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 22, 2026Updated Oct 22, 2026Source checked Oct 22, 2026First seen by HOL Oct 22, 2026Material review Oct 22, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.6
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 8.6. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps vyperlang/vyper (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
vyperlang/vypergeneric	>=0.4.0b1 <=0.5.0b1	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for vyperlang/vyper.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Oct 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 22, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.