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Vulnerabilities

Vulnerability · CVE-2026-40072

web3.py allows you to interact with the Ethereum blockchain using Python.

Published Apr 9, 2026 · catalog updated Jul 13, 2026 · web3.py allows you to

Check if you run it

No confirmed exploitation is on record for CVE-2026-40072. EPSS is 0.31%. Act only if a listed version of web3.py allows you to is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (web3.py allows you to).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.2
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.31%
Remediation
Advisory link
Affected products
PyPI web3 · cpe apeworx/web3.py

## 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

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • PyPI web36.0.0b3 → 7.15.0
  • cpe apeworx/web3.py6.0.0

How to fix CVE-2026-40072

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-40072. EPSS is 0.31%. Act only if a listed version of web3.py allows you to is installed.

Which versions are affected?

Compare what you have installed with 6.0.0b3 → 7.15.0, 6.0.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-918: Server-Side Request Forgery (SSRF). EPSS 0.31%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. 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

  2. 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

  3. Jul 13, 2026 · GitHub Advisory Database

    Fix available

    web3 fixed in 7.15.0

  4. Jul 13, 2026 · GitHub Advisory Database

    Fix available

    web3 fixed in 7.15.0

  5. 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

Sources

  • CVE.orgVulnerability recordCVE-2026-40072

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-40072

    30-day exploitation probability 0.3%

    first.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

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.