AploSec / Disclosures / CVE-2026-111171
Web3.py 7.15.0 through 7.16.0 and 8.0.0b2 through 8.0.0 CCIP-Read SSRF Bypass
CVE-2026-111171 · published 2026-10-15
Summary
Web3.py 7.15.0 through 7.16.0 and 8.0.0b2 through 8.0.0 contains a server-side request forgery vulnerability because _check_ip_blocked() does not unwrap IPv4-mapped IPv6 addresses in CCIP Read URL validation. Malicious contracts can return OffchainLookup URLs with IPv4-mapped IPv6 hosts or AAAA records, making clients with CCIP Read enabled send requests to loopback, private, or link-local services.
Evidence
Reported to the maintainer with a proof of concept that reproduced against the affected release.
Remediation
No fixed release is listed in the advisory. Check the references for upstream status.
References
- Referencehttps://github.com/ethereum/web3.py/security/advisories/GHSA-5hr4-253g-cpx2
- VulnCheck advisoryhttps://www.vulncheck.com/advisories/web3-py-7.15.0-through-7.16.0-and-8.0-0b2-through-8.0.0-ccip-read-ssrf-bypass
- Fix pull requesthttps://github.com/ethereum/web3.py/pull/3875
- Vulnerable codehttps://github.com/ethereum/web3.py/blob/c8c1ed0c9e77e1a8b74902e6a6825e0b00534b10/web3/utils/ccip_url_validation.py#L16-L57
- CVE recordhttps://www.cve.org/CVERecord?id=CVE-2026-111171
- Package
- web3
- Ecosystem
- PyPI
- Weekly downloads
- 1.2M
- Affected
- 7.15.0 through 7.16.0, 8.0.0b2 through 8.0.0
- Fixed
- None
- Weakness
- CWE-918
- CNA
- VulnCheck
- Credit
- SashaMIT, Zachariah Mithani