# GHSA-59qp-cfj3-rp64: netfoil has a domain name filter bypass via multiple questions

> Attackers can bypass domain name filters in the netfoil Go library by crafting DNS requests with multiple questions, potentially evading security controls.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Jul 2026
- **Also known as:** GO-2026-5934

## What is GHSA-59qp-cfj3-rp64?

GHSA-59qp-cfj3-rp64 is a vulnerability in github.com/tinfoil-factory/netfoil, published on 7 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

### Summary
Potential bypass of domain name filter by crafting a DNS request with multiple questions, with the first question being legitimate.

### Impact
Depends on a local attackers ability to craft multiple questions and the remote DoH server supporting them.

## Which versions are affected by GHSA-59qp-cfj3-rp64?

3 open source packages ship an affected version, including github.com/tinfoil-factory/netfoil.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/tinfoil-factory/netfoil` | Go | All versions | 0.3.0 |
| `github.com/tinfoil-factory/netfoil` | Go | All versions | 0.3.0 |
| `github.com/tinfoil-factory/netfoil` | Go | All versions | 0.3.0 |

## How do I fix GHSA-59qp-cfj3-rp64?

Upgrade github.com/tinfoil-factory/netfoil to 0.3.0 or later.

## Is GHSA-59qp-cfj3-rp64 being exploited?

There is no known exploitation of GHSA-59qp-cfj3-rp64 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-59qp-cfj3-rp64 and fix it if it is affected.

What it is: GHSA-59qp-cfj3-rp64 is a vulnerability in github.com/tinfoil-factory/netfoil, published on 7 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-59qp-cfj3-rp64 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/tinfoil-factory/netfoil (Go): affected all versions; fixed in 0.3.0
- github.com/tinfoil-factory/netfoil (Go): affected all versions; fixed in 0.3.0
- github.com/tinfoil-factory/netfoil (Go): affected all versions; fixed in 0.3.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/GHSA-59qp-cfj3-rp64/ (Markdown: https://insights.sbomify.com/GHSA-59qp-cfj3-rp64/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-59qp-cfj3-rp64

---
From sbomify Insights: https://insights.sbomify.com/GHSA-59qp-cfj3-rp64/
Summaries are generated and may contain mistakes; the official description above is the record.