CVE-2021-48019

CVSS 6.3 (medium) · published 2026-10-21

Vyper before 0.2.9 deploys forwarder proxies through the built-in create_forwarder_to function that report a fixed 4096-byte RETURNDATASIZE rather than the actual return data size. Calls through these proxies can yield corrupted data when a function returns more than 4096 bytes without return data sanitation, and fail strict return-size checks such as SafeERC20.safeTransfer.

Weakness: CWE-805

Source: NVD CVE-2021-48019

References

• https://github.com/vyperlang/vyper/security/advisories/GHSA-375m-5fvv-xq23
• https://www.vulncheck.com/advisories/vyper-before-0.2.9-incorrect-returndatasize-in-create-forwarder-to-proxies

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