CVE-2026-30934 FileBrowser Quantum: Stored XSS in public share page via unsanitized share metadata (text/template misuse)
Attackers can inject malicious scripts into share metadata, leading to stored XSS and potential account takeover when victims view public share pages.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-30934?
CVE-2026-30934 is a high-severity cross-site scripting vulnerability in gtsteffaniak filebrowser, published on 10 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
FileBrowser Quantum is a free, self-hosted, web-based file manager. Prior to 1.3.1-beta and 1.2.2-stable, Stored XSS is possible via share metadata fields (e.g., title, description) that are rendered into HTML for /public/share/<hash> without context-aware escaping. The server uses text/template instead of html/template, allowing injected scripts to execute when victims visit the share URL. This vulnerability is fixed in 1.3.1-beta and 1.2.2-stable.
Weakness: CWE-79
Which versions are affected by CVE-2026-30934?
3 open source packages ship an affected version, including github.com/gtsteffaniak/filebrowser. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/gtsteffaniak/filebrowser Go | All versions | 0.0.0-20260307130210-09713b32a5f6 |
github.com/gtsteffaniak/filebrowser Go | All versions | 0.0.0-20260307130210-09713b32a5f6 |
github.com/gtsteffaniak/filebrowser Go | All versions | 0.0.0-20260307130210-09713b32a5f6 |
Products include Filebrowser Filebrowser.
How do I fix CVE-2026-30934?
Upgrade github.com/gtsteffaniak/filebrowser to 0.0.0-20260307130210-09713b32a5f6 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-30934 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-30934 exists.
Other vulnerabilities in gtsteffaniak filebrowser
- CVE-2026-32760 File Browser Self Registration Grants Any User Admin Access When Default Permissions Include Admin
- CVE-2026-29188 File Browser: TUS Delete Endpoint Bypasses Delete Permission Check
- CVE-2023-39612 Cross-site scripting in n/a
- CVE-2021-46398 Cross-Site Request Forgery in Filebrowser
- CVE-2026-35604 File Browser share links remain accessible after Share/Download permissions are revoked
Sources
Also known as GHSA-r633-fcgp-m532, GO-2026-4660.