CVE-2026-72836

The record

FileBrowser before 2.63.19 does not account for case-insensitive filesystems when checking home directory ownership during self-registration. When Signup and CreateUserDir are enabled and FileBrowser's root is on a case-insensitive filesystem (confirmed on Windows/NTFS), two self-registered usernames that differ only in letter case (e.g., CaseVictim and casevictim) are stored as distinct accounts but resolve to the same physical home directory, because the scope-ownership check compares the persisted scope as an exact case-sensitive string. A second registrant can therefore read, overwrite, and delete another account's files through authenticated HTTP endpoints, without needing an existing account or victim interaction.

Affected packages

Related vulnerabilities

• CVE-2026-86472 fast-uri is a dependency-free RFC 3986 URI parser for Node.js, used by Fastify and ajv. CWE-178
• CVE-2026-87876 Two case-insensitive comparisons on request-derived usernames outside the main… CWE-178
• CVE-2026-84428 fastify versions before 5.12.2 implement the case-insensitive nature of HTTP header names… CWE-178
• CVE-2026-84303 gRPC-Go is the Go language implementation of gRPC. CWE-178
• CVE-2026-83612 xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and… CWE-178
• CVE-2026-73270 Improper Handling of Case Sensitivity vulnerability in Erlang/OTP inets httpd allows a… CWE-178
• CVE-2026-82726 Permissive Regular Expression vulnerability in ash-project ash_phoenix lets a remote… CWE-178
• CVE-2026-78959 Improper handling of case sensitivity in FileSystem in Google Chrome prior to… CWE-178