CVE-2026-114115 MEDIUM

CVE-2026-114115: Vyper 0.3.8 through 0.5.0b1 Memory Misread via Ternary Nested Array Selection

Vendor Vyperlang
Product vyper
Weakness CWE-843
Published October 21, 2026
Last update October 21, 2026

CVSS base score

6.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Vyper 0.3.8 through 0.5.0b1 contains a compiler miscompilation vulnerability in parse_IfExp that reads nested arrays with narrower inner bounds using the wider result type's memory layout. When a ternary selects the narrower array, inner arrays after the first are read at wrong offsets, causing contracts to silently store corrupted values or revert.

Key dates

02Disclosure timeline

October 21, 2026 CVE published
October 21, 2026 Record updated