GHSA-2R3X-4MRV-MCXF

Vyper: Memory corruption using function calls within tuples / nested calls

Please see #2186 for further information

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())

Kodem intelligence

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This problem was fixed in #2186, and released as a part of v0.2.6.

1. What is GHSA-2R3X-4MRV-MCXF? GHSA-2R3X-4MRV-MCXF is a medium-severity security vulnerability in vyper (pip), affecting versions < 0.2.6. It is fixed in 0.2.6.
2. Which versions of vyper are affected by GHSA-2R3X-4MRV-MCXF? vyper (pip) versions < 0.2.6 is affected.
3. Is there a fix for GHSA-2R3X-4MRV-MCXF? Yes. GHSA-2R3X-4MRV-MCXF is fixed in 0.2.6. Upgrade to this version or later.
4. Is GHSA-2R3X-4MRV-MCXF exploitable, and should I be worried? Whether GHSA-2R3X-4MRV-MCXF is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether GHSA-2R3X-4MRV-MCXF is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix GHSA-2R3X-4MRV-MCXF? Upgrade vyper to 0.2.6 or later.

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