# 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.

- **Severity:** Low 1.7 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Apr 2026
- **Updated:** 9 Apr 2026

## 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 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-40072?

It affects 1 product.


Products: Apeworx Web3.py.

## How do I fix CVE-2026-40072?

Upgrade to a fixed version.

## 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:

- Hands-on lab for CVE-2026-40072 — SSRF vulnerability in web3.py via CCIP Read (EIP-3668) (github_poc): https://github.com/u1tr0nex/cve-2026-40072-ssrf-lab

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40072 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40072 exists.

Affected product: ethereum web3.py. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-40072/ (Markdown: https://insights.sbomify.com/CVE-2026-40072/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40072
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40072
- OSV: https://osv.dev/vulnerability/CVE-2026-40072

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-40072/
Summaries are generated and may contain mistakes; the official description above is the record.