---
id: CVE-2023-32059
aliases:
  - GHSA-ph9x-4vc9-m39g
  - PYSEC-2023-79
title: >-
  Vyper vulnerable to incorrect ordering of arguments for kwargs passed to
  internal calls
summary: >-
  Vyper vulnerable to incorrect ordering of arguments for kwargs passed to
  internal calls
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'
vendor: vyper
product: vyper
ecosystem: pip
affected:
  - vyper < 0.3.8
patched:
  - vyper 0.3.8
published: '2023-05-12'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:50:01.672293094Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-ph9x-4vc9-m39g'
references:
  - url: 'https://github.com/vyperlang/vyper/security/advisories/GHSA-ph9x-4vc9-m39g'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2023-32059'
  - url: >-
      https://github.com/vyperlang/vyper/commit/c3e68c302aa6e1429946473769dd1232145822ac
  - url: >-
      https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2023-79.yaml
  - url: 'https://github.com/vyperlang/vyper'
tags:
  - osv
  - pip
epss: 0.00725
epssPercentile: 0.52657
ingestedAt: '2026-09-12T03:13:01.716Z'
---

## Overview

### Impact

Internal calls to internal functions with more than 1 default argument are compiled incorrectly. Depending on the number of arguments
provided in the call, the defaults are added not right-to-left, but left-to-right. If the types are incompatible,
typechecking is bypassed. In the `bar()` function in the following code, `self.foo(13)` is compiled to
`self.foo(13,12)` instead of `self.foo(13,1337)`.

```vyper
@internal
def foo(a:uint256 = 12, b:uint256 = 1337):
    pass

@internal
def bar():
    self.foo(13)
```

note that at the time of publication, the ability to pass kwargs to internal functions is an undocumented feature that does not seem to be widely used.

### Patches
patched in c3e68c302aa6e1429946473769dd1232145822ac

### Workarounds
_Is there a way for users to fix or remediate the vulnerability without upgrading?_

### References
_Are there any links users can visit to find out more?_


## Affected packages

- `vyper < 0.3.8`

## Remediation

Upgrade to a patched release:

- `vyper 0.3.8`