CVE-2025-22870: HTTP Proxy bypass using IPv6 Zone IDs in golang.org/x/net

March 12, 2025 (updated April 24, 2026)

Matching of hosts against proxy patterns can improperly treat an IPv6 zone ID as a hostname component. For example, when the NO_PROXY environment variable is set to “*.example.com”, a request to “[::1%25.example.com]:80` will incorrectly match and not be proxied.

References

github.com/advisories/GHSA-qxp5-gwg8-xv66
go.dev/cl/654697
go.dev/issue/71984
groups.google.com/g/golang-announce/c/4t3lzH3I0eI/m/b42ImqrBAQAJ
nvd.nist.gov/vuln/detail/CVE-2025-22870
pkg.go.dev/vuln/GO-2025-3503
security.netapp.com/advisory/ntap-20250509-0007

Code Behaviors & Features

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