Vyper vulnerable to incorrect ordering of arguments for kwargs passed to internal calls

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2023-32059: 0.73% estimated exploitation activity in the next 30 days; percentile 54.13 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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). 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?

Published by the source

12 May 2023, 20:21 UTC

Last modified by the source

10 Sep 2026, 03:50 UTC

Source last checked

26 Oct 2026, 13:27 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-ph9x-4vc9-m39g

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-ph9x-4vc9-m39g

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# Patch Next advisory brief: CVE-2023-32059

Advisory: Vyper vulnerable to incorrect ordering of arguments for kwargs passed to internal calls
IDs: CVE-2023-32059, GHSA-ph9x-4vc9-m39g
Record: https://patchnext.com/advisories/cve-2023-32059 (revision 3, source checked 26 Oct 2026, 13:27 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: vyper 0.3.8. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI vyper: affected < 0.3.8; fixed in 0.3.8

## Suggested inspection (read-only)
- `python -m pip show vyper`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on vyper.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-ph9x-4vc9-m39g (OSV record GHSA-ph9x-4vc9-m39g lists affected ranges: PyPI vyper >=0 <0.3.8 (fixed))
- Verified: https://github.com/advisories/GHSA-ph9x-4vc9-m39g (GitHub-reviewed advisory GHSA-ph9x-4vc9-m39g lists affected ranges: PyPI vyper >=0 <0.3.8)

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