Read the docs
TI-2024-21528 Aliases CVE-2024-32646GHSA-r56x-j438-vw5m

vyper performs double eval of the slice args when buffer from adhoc locations

Priority MEDIUM 57CWE-20Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. In versions 0.3.10 and prior, using the `slice` builtin can result in a double eval vulnerability when the buffer argument is either `msg.data`, `self.code` or `<address>.code` and either the `start` or `length` arguments have side-effects. It can be easily triggered only with the versions `<0.3.4` as `0.3.4` introduced the unique symbol fence. No vulnerable production contracts were found. Additionally, double evaluation of side-effects should be easily discoverable in client tests. As such, the impact is low. As of time of publication, no fixed versions are available.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00451 39th percentileScored 2026-11-07
Fix Fixed vyper (PyPI): 0.4.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
vyperlangvyperup to 0.3.10—No fix listedCNA
—vyper (PyPI)before 0.4.00.4.0Patch availableGHSA-r56x-j438-vw5m
  • vyper Vendorvyperlang Affected up to 0.3.10 Fixed in — No fix listed CNA
  • vyper (PyPI) Vendor— Affected before 0.4.0 Fixed in 0.4.0 Patch available GHSA-r56x-j438-vw5m

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:vyperlang:vyper:*:*:*:*:*:python:*:*before 0.4.0Vulnerablevyperlang
  • cpe:2.3:a:vyperlang:vyper:*:*:*:*:*:python:*:* Versions before 0.4.0 Vulnerable ·vyperlang

Remediation

  • Fix · GHSA-r56x-j438-vw5m vyper (PyPI) Fixed in 0.4.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2024-32646
  2. 2026-10-03 Alias added: GHSA-r56x-j438-vw5m

References

Advisory 2

Other 3

  • TI-2024-16182 Vyper bounds check on built-in `slice()` function can be overflowed CVSS 3.1CRITICAL 9.8
  • TI-2024-14992 concat built-in can corrupt memory in vyper CVSS 3.1CRITICAL 9.8
  • TI-2024-16184 Vyper array negative index vulnerability CVSS 3.1CRITICAL 9.8
  • TI-2022-08657 Integer bounds error in Vyper CVSS 3.1CRITICAL 9.8
  • TI-2022-11796 Multiple evaluation of contract address in call in vyper CVSS 3.1HIGH 8.2
  • TI-2024-21531 vyper performs double eval of the argument of sqrt CVSS 3.1MEDIUM 5.3
See all 37 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences