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.
Published: 2026-10-21
Score: 6.3 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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Advisories

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History

Wed, 21 Oct 2026 00:45:00 +0000

Type Values Removed Values Added
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.
Title Vyper before 0.2.9 Incorrect RETURNDATASIZE in create_forwarder_to Proxies
First Time appeared Vyperlang
Vyperlang vyper
Weaknesses CWE-805
CPEs cpe:2.3:a:vyperlang:vyper:*:*:*:*:*:*:*:*
Vendors & Products Vyperlang
Vyperlang vyper
References
Metrics cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N'}

Subscriptions

Vyperlang Vyper
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-21T00:36:18.960Z

Reserved: 2026-10-20T21:51:44.816Z

Link: CVE-2021-48019

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-21T01:17:19.130

Modified: 2026-10-21T01:17:19.130

Link: CVE-2021-48019

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-805

    Buffer Access with Incorrect Length Value