# CVE-2026-34529: File Browser is vulnerable to Stored Cross-site Scripting via crafted EPUB file

> Attackers can execute arbitrary JavaScript in victims' browsers by uploading crafted EPUB files to File Browser.

- **Severity:** High 7.6 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N`)
- **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:** 1 Apr 2026
- **Updated:** 2 Apr 2026
- **Also known as:** GHSA-5vpr-4fgw-f69h, GO-2026-5156

## What is CVE-2026-34529?

CVE-2026-34529 is a high-severity cross-site scripting vulnerability in filebrowser, published on 1 Apr 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

File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to version 2.62.2, the EPUB preview function in File Browser is vulnerable to Stored Cross-Site Scripting (XSS). JavaScript embedded in a crafted EPUB file executes in the victim's browser when they preview the file. This issue has been patched in version 2.62.2.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-34529?

4 open source packages ship an affected version, including github.com/filebrowser/filebrowser/v2 and github.com/filebrowser/filebrowser. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/filebrowser/filebrowser/v2` | Go | All versions | 2.62.2 |
| `github.com/filebrowser/filebrowser/v2` | Go | All versions | 2.62.2 |
| `github.com/filebrowser/filebrowser/v2` | Go | All versions | 2.62.2 |
| `github.com/filebrowser/filebrowser` | Go | All versions | None |

Products: Filebrowser Filebrowser.

## How do I fix CVE-2026-34529?

Upgrade github.com/filebrowser/filebrowser/v2 to 2.62.2 or later.

## Is CVE-2026-34529 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34529 exists.

## Other vulnerabilities in 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-2026-30934](https://insights.sbomify.com/CVE-2026-30934/): FileBrowser Quantum: Stored XSS in public share page via unsanitized share metadata (text/template misuse) (high 8.9)
- [CVE-2021-46398](https://insights.sbomify.com/CVE-2021-46398/): Cross-Site Request Forgery in Filebrowser (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34529 and fix it if it is affected.

What it is: CVE-2026-34529 is a high-severity cross-site scripting vulnerability in filebrowser, published on 1 Apr 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-2026-34529 exists.

Affected packages and fixed versions:
- github.com/filebrowser/filebrowser/v2 (Go): affected all versions; fixed in 2.62.2
- github.com/filebrowser/filebrowser/v2 (Go): affected all versions; fixed in 2.62.2
- github.com/filebrowser/filebrowser/v2 (Go): affected all versions; fixed in 2.62.2
- github.com/filebrowser/filebrowser (Go): affected all versions; no fix listed

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-2026-34529/ (Markdown: https://insights.sbomify.com/CVE-2026-34529/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34529
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34529
- OSV: https://osv.dev/vulnerability/CVE-2026-34529

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34529/
Summaries are generated and may contain mistakes; the official description above is the record.