CVE-2026-40072
web3.py allows you to interact with the Ethereum blockchain using Python.
Published Apr 9, 2026 · corrected/updated Jul 13, 2026 · apeworx web3.py · evidence confidence high
## Summary web3.py implements CCIP Read / (EIP-3668) by performing HTTP requests to URLs supplied by smart contracts in . The implementation uses these contract-supplied URLs directly (after / template substitution) without any destination validation: - No restriction to (and no opt-in gate for ) - No hostname or IP allowlist - No blocking of private/reserved IP ranges (loopback, link-local, RFC1918) - No redirect target validation (both and follow redirects by default) **CCIP Read is enabled by default** ( on all providers), meaning any application using web3.py's 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 / 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. --- ## Why This Is a Vulnerability The argument is not that CCIP Read itself is invalid or that web3.py should stop supporting EIP-3668. The issue is that, in server-side deployments (backends, indexers, bots, APIs), the current implementation doesn't provide destination policy controls, such as a validation/override hook, private-range blocking, or redirect target checks, which means contract controlled CCIP URLs can be used as an SSRF primitive. This is consistent with EIP-3668's own security considerations, which recommends that client libraries "provide clients with a hook to override CCIP read calls, either by rewriting them to use a proxy service, or by denying them entirely" and that "this mechanism or another should be written so as to easily facilitate adding domains to allowlists or blocklists." The mitigations I'm suggesting are meant to align with that guidance without breaking CCIP Read support. - **Default-on exposure.** CCIP Read is enabled by default on all web3.py providers ( ). User
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-40072 is a high public vulnerability record for apeworx web3.py. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether apeworx web3.py is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: web3 (6.0.0b3 → 7.15.0); apeworx/web3.py; apeworx/web3.py (6.0.0). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 7.2. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-918. Sources contributing to this record: cve_org, github, nvd, osv. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Apr 9, 2026 · NIST NVD
Detected
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 dest
Jun 17, 2026 · NIST NVD
Updated
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 dest
Jul 13, 2026 · GitHub Advisory Database
Fix available
web3 fixed in 7.15.0
Jul 13, 2026 · GitHub Advisory Database
Fix available
web3 fixed in 7.15.0
Jul 13, 2026 · GitHub Advisory Database
Updated
## Summary web3.py implements CCIP Read / (EIP-3668) by performing HTTP requests to URLs supplied by smart contracts in . The implementation uses these contract-supplied URLs directly (after / template substitution) without any destination validation: - No restriction to (and no opt-in gate for ) - No hostname or IP allowlist - No blocking of private/reserved IP ranges (loopback, link-local, RFC19
Affected
- PyPI web36.0.0b3 → 7.15.0
- cpe apeworx/web3.pyversion unspecified
- cpe apeworx/web3.py6.0.0
Sources
- CVE.orgVulnerability recordCVE-2026-40072
Official CVE identifier
cve.org - GitHub Advisory DatabasePackage advisoryGHSA-5hr4-253g-cpx2
GitHub Advisory Database record mirrored by OSV.
github.com - NIST NVDVulnerability recordCVE-2026-40072
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 im
nvd.nist.gov - OpenSSF OSV / OSV ScannerPackage advisoryPYSEC-2026-3414
web3.py: SSRF via CCIP Read (EIP-3668) OffchainLookup URL handling
osv.dev