GitHub Advisoryadvisory · PyPI
GHSA-2r3x-4mrv-mcxf Vyper: Memory corruption using function calls within tuples / nested calls
MEDIUM
Official page ↗
- Ecosystem
- PyPI
- Packages
- vyper
- Severity
- Moderate
- CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- Weaknesses
- CWE-129
- Reviewed
- 2026-10-06
Affected packages
• PyPI vyper: < 0.2.6 → fixed in 0.2.6
Description
Impact
When performing a function call inside a tuple or as an argument inside another function call, there is a memory corruption issue that occurs because of an incorrect pointer to the the tip of the stack.
Example code:
```python
@internal
def _foo(a: uint256, b: uint256, c: uint256) -> (uint256, uint256, uint256, uint256, uint256):
return 1, a, b, c, 5
@internal
def _foo2() -> uint256:
a: uint256[10] = [6,7,8,9,10,11,12,13,15,16]
return 4
@external
def foo() -> (uint256, uint256, uint256, uint256, uint256):
return self._foo(2, 3, self._foo2())
```
Please see #2186 for further information
Patches
This problem was fixed in #2186, and released as a part of `v0.2.6`.
Related
Weakness · CWE (1)
- CWE-129 Improper Validation of Array Index weakness
References
- https://github.com/vyperlang/vyper/security/advisories/GHSA-2r3x-4mrv-mcxf web
- https://github.com/vyperlang/vyper/pull/2186 web
- https://github.com/vyperlang/vyper/commit/74ba67d4bec5f8be4f05759e37d2bfb1463e0441 web
- https://github.com/vyperlang/vyper package
- https://github.com/vyperlang/vyper/releases/tag/v0.2.6 web