mediumCVSS 5.4Vulnerability

GHSA-mmpx-jh39-wrv6

## Summary FileBrowser Quantum serves inline SVG files without a `Content-Security-Policy` header, allowing embedded JavaScript in SVG files to execute when accessed via public share links. Verified on v1.3.0-stable. ## Affected product - **Product:** FileBrowser Quantum (`gtsteffaniak/filebrowser`) - **Verified version:** v1.3.0-stable - **Docker image:** gtstef/filebrowser:latest - **Affected endpoint:** `GET /public/api/resources/download?hash=HASH&inline=true` - **CWE:** CWE-79 — Cross-site Scripting (Stored) ## Impact - **Stored XSS** — Malicious SVG persists and executes for every visitor to the share link - **No authentication required to trigger** — Public share links are accessible to anyone - **Session hijacking** — If authenticated users click the link, their session can be stolen - **Phishing** — Attacker can redirect or overlay fake login forms ## Reproduction 1. Login as any user with upload permission 2. Upload SVG file: ```xml <svg xmlns="http://www.w3.org/2000/svg"> <script>alert(document.domain)</script> </svg> ``` 3. Create public share for the file 4. Access the share link with `?inline=true` 5. JavaScript executes in browser ## Root cause The inline download endpoint returns SVG files with: ``` Content-Type: image/svg+xml Content-Disposition: inline; filename="xss.svg" X-Content-Type-Options: nosniff ``` But no CSP header to block script execution. The upstream project (filebrowser/filebrowser) mitigates this with: ``` Content-Security-Policy: script-src 'none' ``` ## Suggested fix Add CSP header on inline file downloads: ```go w.Header().Set("Content-Security-Policy", "script-src 'none'") ``` This matches the upstream filebrowser/filebrowser implementation.

Properties

ghsa_id
GHSA-mmpx-jh39-wrv6
severity
medium
summary
FileBrowser Vulnerable to Stored XSS via SVG File in Public Share (Missing CSP Header)
cvss_score
5.4
cve_id
GHSA-mmpx-jh39-wrv6
cvss_vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
is_ghsa_only
true
ghsa_published
2026-05-07T03:29:43Z
source_url
https://github.com/advisories/GHSA-mmpx-jh39-wrv6
ghsa_updated
2026-05-07T03:29:43Z

Related Entities (4)

REPORTED_BY (1)

[Source]GitHub Advisory Database

VULNERABLE_TO (1)

[Software]go/github.com/gtsteffaniak/filebrowser

AFFECTS (1)

[Software]go/github.com/gtsteffaniak/filebrowser

HAS_WEAKNESS (1)

[Weakness]Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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