CVE-2026-114115: Access of Resource Using Incompatible Type ('Type Confusion') in vyperlang vyper
Description
Vyper versions 0.3.8 through 0.5.0b1 have a compiler miscompilation vulnerability in the parse_IfExp function. This flaw causes incorrect memory layout handling when reading nested arrays with narrower inner bounds, leading to corrupted stored values or contract reverts when a ternary expression selects the narrower array.
CVSS v4.0
Score 6.3medium
Affected software
vyperlang
vyper
pkg:github/vyperlang/vyperRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-114115 describes a type confusion vulnerability in the Vyper compiler between versions 0.3.8 and 0.5.0b1. The issue occurs in the parse_IfExp function, which miscompiles nested arrays by reading them using the wider result type's memory layout rather than respecting the narrower inner bounds. This results in incorrect offsets being used for inner arrays after the first, causing contracts to either silently store corrupted data or revert during execution.
Potential Impact
The vulnerability can cause smart contracts compiled with affected Vyper versions to store corrupted values or revert unexpectedly. This may lead to unintended contract behavior or failures, potentially impacting contract reliability and correctness. There is no indication of privilege escalation or remote code execution. No known exploits in the wild have been reported.
Mitigation Recommendations
No explicit patch or remediation information is provided in the input data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid using affected Vyper versions for compiling contracts that rely on nested arrays with ternary expressions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-20T21:48:58.503Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ad80c0c2cdf04f6568caa67
Added to database: 10/21/2026, 00:49:16 UTC
Last enriched: 10/21/2026, 01:03:44 UTC
Last updated: 10/21/2026, 01:08:18 UTC
Views: 5
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