CVE-2025-22870

MEDIUM

golang.org/x/net < 0.36.0 and Go net/http < 1.23.7/1.24.0-1.24.1 - Proxy Bypass via IPv6 Zone ID Misinterpretation

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2025-22870. PoCs published by JoshuaProvoste.

AI-analyzed exploit summary This PoC demonstrates CVE-2025-22870, a vulnerability in the `golang.org/x/net/http/httpproxy` package that allows bypassing HTTP proxy restrictions by exploiting IPv6 zone ID parsing flaws in NO_PROXY matching. The exploit sends a crafted request to `[::1%25.example.com]:7777`, which incorrectly matches NO_PROXY rules and evades proxy routing.

Description

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.

Exploits (1)

nomisec WORKING POC 2 stars
by JoshuaProvoste · poc
https://github.com/JoshuaProvoste/CVE-2025-22870

This PoC demonstrates CVE-2025-22870, a vulnerability in the `golang.org/x/net/http/httpproxy` package that allows bypassing HTTP proxy restrictions by exploiting IPv6 zone ID parsing flaws in NO_PROXY matching. The exploit sends a crafted request to `[::1%25.example.com]:7777`, which incorrectly matches NO_PROXY rules and evades proxy routing.

Classification
Working Poc 100%
Attack Type
Ssrf
Complexity
Trivial
Reliability
Reliable
Target: golang.org/x/net/http/httpproxy < 0.36.0
No auth needed
Prerequisites: Vulnerable version of golang.org/x/net/http/httpproxy · NO_PROXY environment variable configured
devstral-2 · analyzed Feb 16, 2026 Full analysis →

Scores

CVSS v3 4.4
EPSS 0.0003
EPSS Percentile 9.8%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-115
Status published
Products (5)
Go standard library/net/http < 1.23.7
Go standard library/net/http 1.24.0-0 - 1.24.1
golang.org/x/net/golang.org/x/net/http/httpproxy < 0.36.0
golang.org/x/net/golang.org/x/net/proxy < 0.36.0
x/net 0 - 0.36.0Go
Published Mar 12, 2025
Tracked Since Feb 18, 2026