Vulnerability in Nhost
CVE-2026-33221
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (10.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 10.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Nhost — versions < 0.12.0
- Nhost Storage
Weakness classification (CWE)
References
- github.com/nhost/nhost/security/advisories/GHSA-g9f6-9775-hffm (Mitigation, Vendor Advisory)
- github.com/nhost/nhost/pull/4018 (Patch, Issue Tracking)
- github.com/nhost/nhost/commit/c4bd53f042d7f568e567e18e2665af81660fce85 (Patch)
- github.com/nhost/nhost/releases/tag/storage@0.12.0 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-33221?
- CVE-2026-33221 is a medium-severity vulnerability in Nhost, classified under CWE-343. CVSS score: 5.3/10. Published 2026-03-20.
- How severe is CVE-2026-33221?
- Medium severity. CVSS v3 base score is 5.3 out of 10.