# GHSA-4ph6-mjv7-3fq6: netfoil vulnerable to improper handling of untrusted DoH response data

> An attacker can cause memory exhaustion or leak sensitive data via logs by sending malicious DNS-over-HTTPS responses to applications using the netfoil library.

- **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:** 24 Aug 2026
- **Also known as:** GO-2026-6277

## What is GHSA-4ph6-mjv7-3fq6?

GHSA-4ph6-mjv7-3fq6 is a vulnerability in github.com/tinfoil-factory/netfoil, published on 24 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

### Summary
HTTPS RR data returned from the DoH server was not properly handled. Unverified APLN data (which could contain arbitrary byte sequences) was written directly to the log. It could also cause unnecessary memory usage. The single-byte response code was also written directly to the log.

## Which versions are affected by GHSA-4ph6-mjv7-3fq6?

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 | 0.5.0 |
| `github.com/tinfoil-factory/netfoil` | Go | All versions | 0.5.0 |
| `github.com/tinfoil-factory/netfoil` | Go | All versions | 0.5.0 |

## How do I fix GHSA-4ph6-mjv7-3fq6?

Upgrade github.com/tinfoil-factory/netfoil to 0.5.0 or later.

## Is GHSA-4ph6-mjv7-3fq6 being exploited?

There is no known exploitation of GHSA-4ph6-mjv7-3fq6 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-4ph6-mjv7-3fq6 and fix it if it is affected.

What it is: GHSA-4ph6-mjv7-3fq6 is a vulnerability in github.com/tinfoil-factory/netfoil, published on 24 Aug 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-4ph6-mjv7-3fq6 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/tinfoil-factory/netfoil (Go): affected all versions; fixed in 0.5.0
- github.com/tinfoil-factory/netfoil (Go): affected all versions; fixed in 0.5.0
- github.com/tinfoil-factory/netfoil (Go): affected all versions; fixed in 0.5.0

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-4ph6-mjv7-3fq6/ (Markdown: https://insights.sbomify.com/GHSA-4ph6-mjv7-3fq6/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-4ph6-mjv7-3fq6

---
From sbomify Insights: https://insights.sbomify.com/GHSA-4ph6-mjv7-3fq6/
Summaries are generated and may contain mistakes; the official description above is the record.