CVE-2025-22870

MEDIUM 4.4

HTTP Proxy bypass using IPv6 Zone IDs in golang.org/x/net

CVSS Score

4.4

EPSS Score

0.0%

EPSS Percentile

9th

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.

Vendor	go standard library
Product	net/http
Published	Mar 12, 2025
Last Updated	Apr 16, 2026

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Affected Versions

Go standard library / net/http

0 < 1.23.7 1.24.0-0 < 1.24.1

golang.org/x/net / golang.org/x/net/http/httpproxy

0 < 0.36.0

golang.org/x/net / golang.org/x/net/proxy

0 < 0.36.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

go.dev: https://go.dev/cl/654697 go.dev: https://go.dev/issue/71984 groups.google.com: https://groups.google.com/g/golang-announce/c/4t3lzH3I0eI/m/b42ImqrBAQAJ pkg.go.dev: https://pkg.go.dev/vuln/GO-2025-3503 openwall.com: http://www.openwall.com/lists/oss-security/2025/03/07/2 security.netapp.com: https://security.netapp.com/advisory/ntap-20250509-0007/

Credits

Juho Forsén of Mattermost