# CVE-2026-33221: Nhost Storage Affected by MIME Type Spoofing via Trusted Client Content-Type Header in Storage Upload


- **Severity:** Low 2.1 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 20 Mar 2026
- **Updated:** 25 Mar 2026
- **Also known as:** GHSA-g9f6-9775-hffm, GO-2026-4759

## What is CVE-2026-33221?

CVE-2026-33221 is a low-severity vulnerability in nhost, published on 20 Mar 2026. 

### Official description

Nhost is an open source Firebase alternative with GraphQL. Prior to version 0.12.0, the storage service's file upload handler trusts the client-provided Content-Type header without performing server-side MIME type detection. This allows an attacker to upload files with an arbitrary MIME type, bypassing any MIME-type-based restrictions configured on storage buckets. This issue has been patched in version 0.12.0.

Weakness: CWE-345 (Insufficient Verification of Data Authenticity), CWE-343 (Predictable Value Range from Previous Values)

## Which versions are affected by CVE-2026-33221?

3 open source packages ship an affected version, including github.com/nhost/nhost. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/nhost/nhost` | Go | All versions | 0.0.0-20260318074820-c4bd53f042d7 |
| `github.com/nhost/nhost` | Go | All versions | 0.0.0-20260318074820-c4bd53f042d7 |
| `github.com/nhost/nhost` | Go | All versions | 0.0.0-20260318074820-c4bd53f042d7 |

Products: Nhost Storage.

## How do I fix CVE-2026-33221?

Upgrade github.com/nhost/nhost to 0.0.0-20260318074820-c4bd53f042d7 or later.

## Is CVE-2026-33221 being exploited?

There is no known exploitation of CVE-2026-33221 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33221 and fix it if it is affected.

What it is: CVE-2026-33221 is a low-severity vulnerability in nhost, published on 20 Mar 2026. 
Exploitation: There is no known exploitation of CVE-2026-33221 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/nhost/nhost (Go): affected all versions; fixed in 0.0.0-20260318074820-c4bd53f042d7
- github.com/nhost/nhost (Go): affected all versions; fixed in 0.0.0-20260318074820-c4bd53f042d7
- github.com/nhost/nhost (Go): affected all versions; fixed in 0.0.0-20260318074820-c4bd53f042d7

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/CVE-2026-33221/ (Markdown: https://insights.sbomify.com/CVE-2026-33221/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33221
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33221
- OSV: https://osv.dev/vulnerability/CVE-2026-33221

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33221/
Summaries are generated and may contain mistakes; the official description above is the record.