CVE-2026-40072 web3.py affected by SSRF via CCIP Read (EIP-3668) OffchainLookup URL handling
Malicious smart contracts can force web3.py to send HTTP requests to arbitrary internal or external URLs, enabling Server-Side Request Forgery attacks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-40072?
CVE-2026-40072 is a low-severity server-side request forgery vulnerability in ethereum web3.py, published on 9 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-918
Which versions are affected by CVE-2026-40072?
It affects 1 product.
Products include Apeworx Web3.py.
How do I fix CVE-2026-40072?
Upgrade to a fixed version.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-40072 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40072 exists.
Public exploit code: 1 proofs of concept on GitHub.