CVE-2021-48019
Medium
Description
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.
SeverityMedium
CVSS4.8
Exploit probability—
Product
Vyper
PublishedOct 21, 2026
First seenOct 21, 2026
Weakness typeCWE-805CWE-805
How to fix
Update
- vyper0.2.9 or later
Vendor advisories
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| vyperPyPI | v < 0.2.9 | 0.2.9 |
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