CVE-2026-54093: File Browser: Path traversal in download-as-zip/tar via Windows-style backslash separators in stored filenames

Severity: medium (CVSS 6.8 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-25 · updated 2026-06-25
Weakness: CWE-22

Description

File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to 2.63.6, filebrowser builds the download-as-zip / download-as-tar archive entry names with filepath.ToSlash, which on a Linux host is a no-op for backslashes (\ is only a path separator on Windows). A file whose name contains Windows-style traversal is accepted by the resource handlers, stored on the Linux filesystem with a literal backslash name, and then emitted verbatim as the archive entry name. Windows extractors interpret \ as a path separator and write the extracted file outside the extraction directory — arbitrary file write on the victim who downloads and extracts the archive. This vulnerability is fixed in 2.63.6.

Affected products

filebrowser: before 2.63.6

References

Get alerted when CVE-2026-54093 or the next vulnerability affects your stack