Description
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.
References6
- github.com/ethereum/web3.py
- github.com/ethereum/web3.py/blob/c8c1ed0c9e77e1a8b74902e6a6825e…
- github.com/ethereum/web3.py/pull/3875
- github.com/ethereum/web3.py/security/advisories/GHSA-5hr4-253g-…
- www.vulncheck.com/advisories/web3-py-7.15.0-through-7.16.0-and-…
- github.com/ApeWorX/web3.py/security/advisories/GHSA-5hr4-253g-c…
Metrics
- CVSS 3.1
-
5.4
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N - CVSS 4.0
-
6.3
MEDIUM
Score source: CNA
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 28 · as of 10 November 2026
- CWE
- CWE-918
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.