Vulnerability in Vyperlang Vyper
CVE-2026-114117
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.
Published .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-6j9c-gvcw-74fj) (vendor-advisory)
- VulnCheck Advisory: Vyper 0.3.8 through 0.5.0b1 Optimizer Miscompilation of msg.value | K in Ternary Branches (third-party-advisory)
Frequently asked questions
- What is CVE-2026-114117?
- CVE-2026-114117 is a medium-severity vulnerability in Vyperlang Vyper, classified under Incorrect Calculation. CVSS score: 5.9/10. Published 2026-10-21.
- How severe is CVE-2026-114117?
- Medium severity. CVSS v3 base score is 5.9 out of 10.