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.
Published: 2026-10-21
Score: 8.2 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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Advisories

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History

Wed, 21 Oct 2026 00:45:00 +0000

Type Values Removed Values Added
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.
Title Vyper 0.3.8 through 0.5.0b1 Optimizer Miscompilation of msg.value | K in Ternary Branches
First Time appeared Vyperlang
Vyperlang vyper
Weaknesses CWE-682
CPEs cpe:2.3:a:vyperlang:vyper:*:*:*:*:*:*:*:*
Vendors & Products Vyperlang
Vyperlang vyper
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N'}

cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}

Subscriptions

Vyperlang Vyper
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-21T00:37:14.741Z

Reserved: 2026-10-20T21:48:58.503Z

Link: CVE-2026-114117

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-21T01:17:38.070

Modified: 2026-10-21T01:17:38.070

Link: CVE-2026-114117

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses