high · 8.3 Patched

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

CVE-2020-37286 · GHSA-3w56-2qv9-5m4p · EUVD-2020-31282 · GHSA-2r3x-4mrv-mcxf · published 6 Oct 2026

How serious is it

  • Severity: high, CVSS score 8.3 out of 10.
  • No exploit prediction (EPSS) score yet.
  • Not on the CISA list of exploited vulnerabilities.
  • No public exploit in Exploit-DB.

Is your app affected by CVE-2020-37286?

Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.

Who is affected

  • vyper (PyPI) < 0.2.6

How to check

  1. Run pip show vyper in your project to see the installed version, including copies pulled in by other packages.
  2. Or paste your lockfile into the checker: it lists every package with a known vulnerability, this one included.
  3. Or run npx shippable-dev scan localhost:3000 in your project folder. It reads your lockfile and flags this vulnerability along with every other known one.

How to fix

Copies a prompt for Claude Code, Cursor or Codex: it checks your lockfiles for this and upgrades it.
  1. Upgrade vyper to 0.2.6 or later, commit the lockfile and redeploy.
  2. If a vulnerable version was live, check your logs and rotate the secrets that server could read.

The advisory

### 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`](https://github.com/vyperlang/vyper/releases/tag/v0.2.6).

Check your whole app

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References

Merged from OSV, ENISA EUVD. Last updated 28 Oct 2026. All vulnerabilities · RSS · JSON

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