How severe is CVE-2023-32059?

CVE-2023-32059 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-32059?

CVE-2023-32059 affects the following packages: vyper (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2023-32059?

Update vyper to 0.3.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-32059 is resolved across your whole dependency graph.

How do I detect CVE-2023-32059 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vyper, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2023-32059 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2023-32059 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2023-32059, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2023-32059?

CVE-2023-32059 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 54th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-32059?

CVE-2023-32059 is classified as CWE-683 (CWE-683). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2023-32059 published, and has it been updated?

CVE-2023-32059 was published on May 11, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

HIGH severity

CVE-2023-32059 — vyper

HIGHFix: vyperlang/vyper@c3e68c3

CVE-2023-32059 is a high-severity (CVSS 7.5) CWE-683 vulnerability in vyper. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for vyper — see the affected versions and patch details below.

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

Also known asGHSA-ph9x-4vc9-m39gPYSEC-2023-79

Published

May 11, 2023

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Nov 1, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-32059.

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs54th percentile — riskier than 54% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐍vyper

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

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).

@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

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`vyper`	all versions	0.3.8`pip install --upgrade 'vyper==0.3.8'`

Affected Products

1 product · 1 configurations

Application

vypervyperlang

< 0.3.8

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Vyper is a Pythonic smart contract language for the Ethereum virtual mac…

github.comNVDMay 2023

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vyper, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update vyper to 0.3.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-32059 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### 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 int