# 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.

- **Severity:** High 8.9 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L`)
- **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:** Yes
- **Published:** 10 Mar 2026
- **Updated:** 10 Mar 2026
- **Also known as:** GHSA-r633-fcgp-m532, GO-2026-4660

## 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 (Improper Neutralization of Input During Web Page Generation)

## 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 | Ecosystem | 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: Filebrowser Filebrowser.

## How do I fix CVE-2026-30934?

Upgrade github.com/gtsteffaniak/filebrowser to 0.0.0-20260307130210-09713b32a5f6 or later.

## 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](https://insights.sbomify.com/CVE-2026-32760/): File Browser Self Registration Grants Any User Admin Access When Default Permissions Include Admin (critical 10.0)
- [CVE-2026-29188](https://insights.sbomify.com/CVE-2026-29188/): File Browser: TUS Delete Endpoint Bypasses Delete Permission Check (critical 9.1)
- [CVE-2023-39612](https://insights.sbomify.com/CVE-2023-39612/): Cross-site scripting in n/a (critical 9.0)
- [CVE-2021-46398](https://insights.sbomify.com/CVE-2021-46398/): Cross-Site Request Forgery in Filebrowser (high 8.8)
- [CVE-2026-35604](https://insights.sbomify.com/CVE-2026-35604/): File Browser share links remain accessible after Share/Download permissions are revoked (high 8.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-30934 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-30934 exists.

Affected packages and fixed versions:
- github.com/gtsteffaniak/filebrowser (Go): affected all versions; fixed in 0.0.0-20260307130210-09713b32a5f6
- github.com/gtsteffaniak/filebrowser (Go): affected all versions; fixed in 0.0.0-20260307130210-09713b32a5f6
- github.com/gtsteffaniak/filebrowser (Go): affected all versions; fixed in 0.0.0-20260307130210-09713b32a5f6

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-30934/ (Markdown: https://insights.sbomify.com/CVE-2026-30934/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-30934
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-30934
- OSV: https://osv.dev/vulnerability/CVE-2026-30934

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-30934/
Summaries are generated and may contain mistakes; the official description above is the record.