Vyper: Memory corruption using function calls within tuples / nested callsGHSA-2r3x-4mrv-mcxf
Fix: vyperlang/vyper#2186GHSA-2r3x-4mrv-mcxf is a remote code execution vulnerability in vyper. A fix is available for vyper — see the affected versions and patch details below.
Real-World Exposure
vyperReal-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
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:
@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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | vyper | all versions | 0.2.6pip install --upgrade 'vyper==0.2.6' |
Detection & mitigation playbook
Open-source dependencyDetect
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 0.2.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-2r3x-4mrv-mcxf is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.
Frequently Asked Questions
Is GHSA-2r3x-4mrv-mcxf in your dependencies?
Find it across PyPI, including transitive dependencies.