# CVE-2026-62843: File Browser path traversal in archive builder via backslash filenames

Source: https://junglewise.ai/threats/cve-2026-62843-file-browser-path-traversal-in-archive-builder-via-backslash  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-15. Updated: 2026-07-20  
License: CC BY 4.0 with a link back

CVE-2026-62843 · Severity: medium · CVSS 6.8 · Published 2026-07-15

File Browser is a web-based file management utility. A vulnerability in its archive creation feature allows users with upload permissions to plant malicious files that, when downloaded and extracted by another user, can write files to arbitrary locations on the victim's computer. This could lead to the overwrite of sensitive system files or the execution of malicious code on the victim's machine.

Technologies: [File Browser](https://junglewise.ai/threats/technologies/file-browser), [Filebrowser](https://junglewise.ai/threats/technologies/filebrowser), [github.com/filebrowser/filebrowser (Go)](https://junglewise.ai/threats/technologies/github-com-filebrowser-filebrowser), [github.com/filebrowser/filebrowser/v2 (Go)](https://junglewise.ai/threats/technologies/github-com-filebrowser-filebrowser-v2). Vendors: [File Browser](https://junglewise.ai/threats/vendors/file-browser), [FileBrowser](https://junglewise.ai/threats/vendors/filebrowser), [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-62843 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-62843 being exploited in the wild.

**How severe is CVE-2026-62843?** Medium severity, with a CVSS score of 6.8, published 15 July 2026.

**Which products and versions are affected?** File Browser >= 2.63.6, < 2.63.17; Filebrowser >= 2.63.6, <= 2.63.16; github.com/filebrowser/filebrowser (Go) SEMVER:introduced=0; github.com/filebrowser/filebrowser/v2 (Go) >= 2.63.6, <= 2.63.16, SEMVER:introduced=2.63.6,fixed=2.63.17.

**Is there a fix for CVE-2026-62843?** Yes. github.com/filebrowser/filebrowser/v2 (Go): upgrade to 2.63.17 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-62843 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-62843?** Check whether you run File Browser, Filebrowser, github.com/filebrowser/filebrowser (Go) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/filebrowser/filebrowser/v2 (Go): upgrade to 2.63.17 or later

  ```sh
  go get github.com/filebrowser/filebrowser/v2@v2.63.17
  ```


## Technical details

A path traversal vulnerability (Zip-Slip) exists in File Browser's archive builder. The root cause is an improper fix for a previous vulnerability where backslashes in filenames are unconditionally replaced with forward slashes. On POSIX systems (Linux/macOS), backslashes are legal filename characters; replacing them with slashes manufactures a traversal sequence (e.g., '..\\..\\' becomes '../../'). An attacker with 'Create' permissions can upload a file with a crafted name containing backslashes. When a victim downloads the containing folder as a ZIP or Tar archive, the resulting archive contains entries that escape the extraction directory. This affects versions 2.63.6 through 2.63.16 and is fixed in 2.63.17.

## Affected products

- filebrowser filebrowser >= 2.63.6, <= 2.63.16

## Identifiers

- CVE-2026-62843
- GHSA-83xp-526h-j3ww
- GO-2026-6026

## Timeline

- 2026-07-04: disclosed
- 2026-07-20: advisory
- 2026-07-20: patched: Fixed in version 2.63.17

## References

- [https://api.github.com/users/je-lv](https://api.github.com/users/je-lv)
- [https://github.com/je-lv](https://github.com/je-lv)
- [https://api.github.com/users/je-lv/gists%7B/gist_id%7D](https://api.github.com/users/je-lv/gists%7B/gist_id%7D)
- [https://api.github.com/users/je-lv/repos](https://api.github.com/users/je-lv/repos)
- [https://avatars.githubusercontent.com/u/40743233?v=4](https://avatars.githubusercontent.com/u/40743233?v=4)
- [https://api.github.com/users/je-lv/events%7B/privacy%7D](https://api.github.com/users/je-lv/events%7B/privacy%7D)

## Related threats

- [File Browser symlink alias path traversal bypass](https://junglewise.ai/threats/cve-2026-90930-file-browser-symlink-alias-path-traversal-bypass)
- [File Browser authorization bypass in direct-upload endpoint](https://junglewise.ai/threats/cve-2026-90929-file-browser-authorization-bypass-in-direct-upload-endpoint)
- [File Browser subtitle conversion memory exhaustion](https://junglewise.ai/threats/cve-2026-90928-file-browser-subtitle-conversion-memory-exhaustion)
- [filebrowser WebSocket message denial of service in /api/command](https://junglewise.ai/threats/cve-2026-90927-filebrowser-websocket-message-denial-of-service-in-api-command)
- [filebrowser race condition in TUS upload handler](https://junglewise.ai/threats/cve-2026-82238-filebrowser-race-condition-in-tus-upload-handler)