# CVE-2026-62685: File Browser: Colliding username normalization gives two users the same home directory

> Attackers can register usernames that normalize to existing users, gaining unauthorized read and write access to another user's files.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Jul 2026
- **Updated:** 20 Jul 2026
- **Also known as:** GHSA-7rc3-g7h6-22m7, GO-2026-6024

## What is CVE-2026-62685?

CVE-2026-62685 is a high-severity vulnerability in filebrowser, published on 15 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to 2.63.17, File Browser builds new user scopes from usernames passed through cleanUsername() when Signup=true and CreateUserDir=true, but the many-to-one normalization can collapse usernames such as team/one, team one, and team-one to the same home directory without checking whether the resulting scope is already taken, allowing a second registrant to gain full read and write access to another user's files. This issue is fixed in version 2.63.17.

Weakness: CWE-706 (Use of Incorrectly-Resolved Name or Reference), CWE-647 (Use of Non-Canonical URL Paths for Authorization Decisions)

## Which versions are affected by CVE-2026-62685?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/filebrowser/filebrowser/v2` | Go | All versions | 2.63.17 |
| `github.com/filebrowser/filebrowser/v2` | Go | All versions | 2.63.17 |
| `github.com/filebrowser/filebrowser/v2` | Go | All versions | 2.63.17 |
| `github.com/filebrowser/filebrowser` | Go | All versions | None |

## How do I fix CVE-2026-62685?

Upgrade github.com/filebrowser/filebrowser/v2 to 2.63.17 or later.

## Is CVE-2026-62685 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-62685 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-62685 and fix it if it is affected.

What it is: CVE-2026-62685 is a high-severity vulnerability in filebrowser, published on 15 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-62685 exists.

Affected packages and fixed versions:
- github.com/filebrowser/filebrowser/v2 (Go): affected all versions; fixed in 2.63.17
- github.com/filebrowser/filebrowser/v2 (Go): affected all versions; fixed in 2.63.17
- github.com/filebrowser/filebrowser/v2 (Go): affected all versions; fixed in 2.63.17
- 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-2026-62685/ (Markdown: https://insights.sbomify.com/CVE-2026-62685/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-62685
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-62685
- OSV: https://osv.dev/vulnerability/CVE-2026-62685

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-62685/
Summaries are generated and may contain mistakes; the official description above is the record.