CVE-2022-29255Network attack vector

Incorrect contract outcomes via double address evaluation

Published Jun 6, 2022 · Updated Apr 22, 2025

Incorrect control flow in Vyper before 0.3.4 allows remote attackers to alter contract outcomes when external calls omit return values. The compiler evaluates the external contract address expression twice, repeating side effects and potentially changing which address or state is used for the call. Exploitation requires a contract compiled with an affected Vyper version and a call expression whose address computation has side effects; the consequence is integrity-impacting, incorrect contract execution rather than direct data disclosure.

CVSS severity7.5
High
EPSS probability1.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect control flow in Vyper before 0.3.4 allows remote attackers to alter contract outcomes when external calls omit return values. The compiler evaluates the external contract address expression twice, repeating side effects and potentially changing which address or state is used for the call. Exploitation requires a contract compiled with an affected Vyper version and a call expression whose address computation has side effects; the consequence is integrity-impacting, incorrect contract execution rather than direct data disclosure.

The record

CVE
CVE-2022-29255
Published
Jun 6, 2022
Updated
Apr 22, 2025
Vendor
Vyper
Product
Vyper
Classifications
CWE-670
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 6, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.3.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Vyper · Vyperversion=< 0.3.4

Published CVSS scores

5.0NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-670Always-Incorrect Control Flow Implementation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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