GHSA-68J5-4M99-W9W9
Vulnerability from github – Published: 2026-03-18 12:59 – Updated: 2026-03-20 21:16Summary
A permission enforcement flaw allows users without download privileges (download=false) to still expose and retrieve file content via public share links when they retain share privileges (share=true). This bypasses intended access control policy and enables unauthorized data exfiltration to unauthenticated users. Where download restrictions are used for data-loss prevention or role separation.
Details
The backend applies inconsistent authorization checks across download paths:
- Direct raw download correctly enforces
Perm.Download: - [raw.go](https://github.com/filebrowser/filebrowser/blob/master/http/raw.go#82)
- Share creation only enforces
Perm.Share: - [share.go](https://github.com/filebrowser/filebrowser/blob/master/http/share.go#21)
- Public share/download handlers serve shared content without verifying owner
Perm.Download: - public.go(filebrowser/http/public.go:18)
- public.go(filebrowser/http/public.go:116)
As a result, a user who is blocked from direct downloads can create a share and obtain the same file via /api/public/dl/<hash>.
PoC
- Create a non-admin user with:
perm.share = true-
perm.download = false -
Login as that user and upload a PDF file:
-
POST /api/resources/nodl_secret_<rand>.pdfwithContent-Type: application/pdf -
Verify direct raw download is denied:
GET /api/raw/nodl_secret_<rand>.pdf-
Expected and observed:
202 Accepted(blocked) -
Create share for same file:
POST /api/share/nodl_secret_<rand>.pdf-
Observed:
200, response includeshash(example:qxfK3JMG) -
Download publicly without authentication:
GET /api/public/dl/<hash>- Observed (vulnerable):
200,Content-Type: application/pdf, and PDF bytes are returned
Live evidence captured (March 1, 2026):
- create user: 201
- create file: 200
- direct /api/raw: 202 Accepted
- create share: 200
- public download /api/public/dl/mxK-ppZb: 200
- public download content-type: application/pdf
- public download body length: 327 bytes
Impact
This is an access control / authorization policy bypass vulnerability.
- Who can exploit: Any authenticated user granted
share=truebut denieddownload. - Who is impacted: Operators and organizations relying on download restrictions to prevent data export.
- What can happen: Restricted users can still distribute and retrieve files publicly, including unauthenticated access through share URLs.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "https://github.com/filebrowser/filebrowser"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "2.61.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-32761"
],
"database_specific": {
"cwe_ids": [
"CWE-284",
"CWE-639",
"CWE-863"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-18T12:59:12Z",
"nvd_published_at": "2026-03-20T00:16:17Z",
"severity": "MODERATE"
},
"details": "### Summary\nA permission enforcement flaw allows users without download privileges (`download=false`) to still expose and retrieve file content via public share links when they retain share privileges (`share=true`). This bypasses intended access control policy and enables unauthorized data exfiltration to unauthenticated users. Where download restrictions are used for data-loss prevention or role separation.\n\n### Details\nThe backend applies inconsistent authorization checks across download paths:\n\n- Direct raw download correctly enforces `Perm.Download`:\n - [[raw.go](https://github.com/filebrowser/filebrowser/blob/master/http/raw.go#82)](filebrowser/http/raw.go:82)\n- Share creation only enforces `Perm.Share`:\n - [[share.go](https://github.com/filebrowser/filebrowser/blob/master/http/share.go#21)](filebrowser/http/share.go:21)\n- Public share/download handlers serve shared content without verifying owner `Perm.Download`:\n - [public.go](https://github.com/filebrowser/filebrowser/blob/master/http/public.go#18)(filebrowser/http/public.go:18)\n - [public.go](https://github.com/filebrowser/filebrowser/blob/master/http/public.go#116)(filebrowser/http/public.go:116)\n\nAs a result, a user who is blocked from direct downloads can create a share and obtain the same file via `/api/public/dl/\u003chash\u003e`.\n\n### PoC\n\n1. Create a non-admin user with:\n- `perm.share = true`\n- `perm.download = false`\n\n2. Login as that user and upload a **PDF** file:\n- `POST /api/resources/nodl_secret_\u003crand\u003e.pdf` with `Content-Type: application/pdf`\n\n3. Verify direct raw download is denied:\n- `GET /api/raw/nodl_secret_\u003crand\u003e.pdf`\n- Expected and observed: `202 Accepted` (blocked)\n\n4. Create share for same file:\n- `POST /api/share/nodl_secret_\u003crand\u003e.pdf`\n- Observed: `200`, response includes `hash` (example: `qxfK3JMG`)\n\n5. Download publicly without authentication:\n- `GET /api/public/dl/\u003chash\u003e`\n- Observed (vulnerable): `200`, `Content-Type: application/pdf`, and PDF bytes are returned\n\nLive evidence captured (March 1, 2026):\n- `create user`: `201`\n- `create file`: `200`\n- `direct /api/raw`: `202 Accepted`\n- `create share`: `200`\n- `public download /api/public/dl/mxK-ppZb`: `200`\n- `public download content-type`: `application/pdf`\n- `public download body length`: `327` bytes\n\n### Impact\nThis is an **access control / authorization policy bypass** vulnerability.\n\n- **Who can exploit:** Any authenticated user granted `share=true` but denied `download`.\n- **Who is impacted:** Operators and organizations relying on download restrictions to prevent data export.\n- **What can happen:** Restricted users can still distribute and retrieve files publicly, including unauthenticated access through share URLs.",
"id": "GHSA-68j5-4m99-w9w9",
"modified": "2026-03-20T21:16:13Z",
"published": "2026-03-18T12:59:12Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/filebrowser/filebrowser/security/advisories/GHSA-68j5-4m99-w9w9"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-32761"
},
{
"type": "WEB",
"url": "https://github.com/filebrowser/filebrowser/commit/09a26166b4f79446e7174c017380f6db45444e32"
},
{
"type": "PACKAGE",
"url": "https://github.com/filebrowser/filebrowser"
},
{
"type": "WEB",
"url": "https://github.com/filebrowser/filebrowser/releases/tag/v2.62.0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
],
"summary": "File Browser has an Authorization Policy Bypass in Public Share Download Flow"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.