CVE-2026-33221: Github.com/nhost/nhost Nhost Storage Affected By MIME Vulnerability
LOWCVE-2026-33221 is a LOW (CVSS 5.3) nhost storage affected by mime vulnerability (CWE-434: Unrestricted Upload of File with Dangerous Type) affecting Github.com/nhost/nhost libraries in the Go ecosystem. The issue involves nhost storage affected by mime type spoofing via trusted client content-type header in storage upload. Remediation is available by upgrading affected packages to version 0.0.0-20260318074820-c4bd53f042d7.
CVE-2026-33221 at a Glance
Security Impact
CVSS: 5.3
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N).
How to Fix CVE-2026-33221
To remediate this vulnerability, upgrade all affected Github.com/nhost/nhost dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/nhost/nhost to 0.0.0-20260318074820-c4bd53f042d7Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/nhost/nhostHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-33221, inspect your project dependencies for Github.com/nhost/nhost:
inspect dependencies for github.com/nhost/nhostAnalyze the terminal output to locate any version of Github.com/nhost/nhost in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.0.0-20260318074820-c4bd53f042d7), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-434: Unrestricted Upload of File with Dangerous Type, where the product allows the upload or transfer of dangerous file types that are automatically processed within its environment. In Github.com/nhost/nhost, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-33221 Affected Github.com/nhost/nhost Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/nhost/nhost
|
Go |
< 0.0.0-20260318074820-c4bd53f042d7
|
0.0.0-20260318074820-c4bd53f042d7
|
References
Frequently Asked Questions
What is CVE-2026-33221?
Which Github.com/nhost/nhost versions are affected?
What version fixes CVE-2026-33221?
Is github.com/nhost/nhost affected?
What is the CVSS score of CVE-2026-33221?
What CWE is associated with CVE-2026-33221?
How can I check Go dependencies for CVE-2026-33221?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-g9f6-9775-hffm",
"modified" : "2026-06-09T11:52:21Z",
"published" : "2026-03-18T20:21:37Z",
"aliases" : [ "CVE-2026-33221" ],
"summary" : "Nhost Storage Affected by MIME Type Spoofing via Trusted Client Content-Type Header in Storage Upload",
"details" : "## Summary\n\nThe 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.\n\n## Affected Component\n\n- **Service**: `services/storage`\n- **File**: `services/storage/controller/upload_files.go`\n- **Function**: `getMultipartFile` (lines 48-70)\n\n## Root Cause\n\nIn `getMultipartFile`, if the client provides a non-empty `Content-Type` header that isn't `application/octet-stream`, the function returns it as-is without performing content-based detection:\n\n```go\ncontentType := file.header.Header.Get(\"Content-Type\")\nif contentType != \"\" && contentType != \"application/octet-stream\" {\n return fileContent, contentType, nil // skip detection entirely\n}\n\n// mimetype.DetectReader only reached if client sends no Content-Type\n// or sends application/octet-stream\nmt, err := mimetype.DetectReader(fileContent)\n```\n\n## Impact\n\n**Incorrect MIME type in file metadata.** The MIME type stored in file metadata reflects what the client claims rather than what the file actually contains. Any system consuming this metadata (browsers, CDNs, applications) may handle the file incorrectly based on the spoofed type.\n\n## Suggested Fix\n\nAlways detect MIME type from file content using `mimetype.DetectReader`, ignoring the client-provided `Content-Type` header entirely.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"
}, {
"type" : "CVSS_V4",
"score" : "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"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/nhost/nhost"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.0.0-20260318074820-c4bd53f042d7"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/nhost/nhost/security/advisories/GHSA-g9f6-9775-hffm"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33221"
}, {
"type" : "WEB",
"url" : "https://github.com/nhost/nhost/pull/4018"
}, {
"type" : "WEB",
"url" : "https://github.com/nhost/nhost/commit/c4bd53f042d7f568e567e18e2665af81660fce85"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/nhost/nhost"
}, {
"type" : "WEB",
"url" : "https://github.com/nhost/nhost/releases/tag/storage%400.12.0"
}, {
"type" : "WEB",
"url" : "https://github.com/nhost/nhost/releases/tag/storage@0.12.0"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-343", "CWE-345", "CWE-434" ],
"severity" : "LOW",
"github_reviewed" : true,
"github_reviewed_at" : "2026-03-18T20:21:37Z",
"nvd_published_at" : "2026-03-20T23:16:46Z"
}
}