CVE-2022-29255: Multiple evaluation of contract address in call in vyper

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2022-06-09 · updated 2026-06-17
Weakness: CWE-670

Description

Vyper is a Pythonic Smart Contract Language for the ethereum virtual machine. In versions prior to 0.3.4 when a calling an external contract with no return value, the contract address (including side effects) could be evaluated twice. This may result in incorrect outcomes for contracts. This issue has been addressed in v0.3.4.

Affected products

vyperlang vyper: before 0.3.4 — fixed in 0.3.4

How to fix

Upgrade to a fixed version: vyperlang vyper 0.3.4. Check the vendor advisory for mitigations.

References

https://github.com/vyperlang/vyper/commit/6b4d8ff185de071252feaa1c319712b2d6577f8d
https://github.com/vyperlang/vyper/security/advisories/GHSA-4v9q-cgpw-cf38
https://github.com/vyperlang/vyper/commit/6b4d8ff185de071252feaa1c319712b2d6577f8d
https://github.com/vyperlang/vyper/security/advisories/GHSA-4v9q-cgpw-cf38

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