Vulnerability · Published Apr 9, 2026 · Assigned by GitHub_M
CVE-2026-40072web3.py affected by SSRF via CCIP Read (EIP-3668) OffchainLookup URL handling
Low 1.7
In plain English
A low-severity server-side request forgery in web3.py from ethereum. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 15% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
web3.py allows you to interact with the Ethereum blockchain using Python. From 6.0.0b3 to before 7.15.0 and 8.0.0b2, web3.py implements CCIP Read / OffchainLookup (EIP-3668) by performing HTTP requests to URLs supplied by smart contracts in offchain_lookup_payload["urls"]. The implementation uses these contract-supplied URLs directly (after {sender} / {data} template substitution) without any destination validation. CCIP Read is enabled by default (global_ccip_read_enabled = True on all providers), meaning any application using web3.py's .call() method is exposed without explicit opt-in. This results in Server-Side Request Forgery (SSRF) when web3.py is used in backend services, indexers, APIs, or any environment that performs eth_call / .call() against untrusted or user-supplied contract addresses. A malicious contract can force the web3.py process to issue HTTP requests to arbitrary destinations, including internal network services and cloud metadata endpoints. This vulnerability is fixed in 7.15.0 and 8.0.0b2.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | web3 | 7.15.0 | GHSA-5hr4-253g-cpx2 |
| PyPI | web3 | 8.0.0b2 | GHSA-5hr4-253g-cpx2 |
| PyPI | web3 | 7.15.0, 8.0.0b2 | PYSEC-2026-3414 |
Affected products (as reported)
Weakness: CWE-918 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U