CVE-2026-114117GHSA-6j9c-gvcw-74fj
Vyper 0.3.8 through 0.5.0b1 Optimizer Miscompilation of msg.value | K in Ternary Branches
vyperlang vyper
CVSS
8.2HighExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 21 Oct 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)0.21%Chance of exploitation activity in the next 30 days, higher than 10% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
What fixes it
No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.
Description
Vyper 0.3.8 through 0.5.0b1 contains an optimizer miscompilation in which (msg.value | K) or (len(msg.data) | K), where K is any nonzero integer literal, is compiled to the constant 1 when used as a ternary expression branch under -O gas (the default) or -O codesize. Affected contracts use the wrong value in storage writes, arithmetic, indexes, return values, or events without warning or revert, which can record deposits incorrectly and lock funds.
Text from CVE List
Affected versions 1
- vyperaffected: 0.3.8 through 0.5.0b1CVE List