CVE-2026-54097

A low-privileged authenticated user of filebrowser (with create + delete permissions in their own isolated scope) can silently destroy share-link records belonging to any other user, including the administrator, by performing a legitimate DELETE on a file in their own directory whose logical path happens to be a byte-prefix of another user's stored share.Link.Path. The file contents of the victim are not exposed, but the victim's share links are irrevocably wiped.

Details

resourceDeleteHandler in http/resource.go cleans up any share records that reference a deleted file by calling:

// http/resource.go
err = d.store.Share.DeleteWithPathPrefix(file.Path)

file.Path here is the logical path from the URL of the deleting user's request (e.g. /a), not the absolute filesystem path. It is passed as-is to the bolt backend:

// storage/bolt/share.go
func (s shareBackend) DeleteWithPathPrefix(pathPrefix string) error {
    var links []share.Link
    if err := s.db.Prefix("Path", pathPrefix, &links); err != nil {
        return err
    }
    for _, link := range links {
        err = errors.Join(err, s.db.DeleteStruct(&share.Link{Hash: link.Hash}))
    }
    return err
}

Why the design contradicts this behavior. share.Link carries a UserID field and the application elsewhere treats shares as per-user owned resources. shareDeleteHandler explicitly enforces link.UserID != d.user.ID && !d.user.Perm.Admin → 403. The file-deletion side-effect path is the only location that bypasses this rule.

• Integrity: unauthorized deletion of share-link metadata belonging to arbitrary users, including administrators.
• Availability: effective denial-of-service of the share-link feature, a cooperating (or malicious) low-priv user can wipe the bulk of existing share links by iterating a short set of one- and two-character prefixes.

Kodem intelligence

1. What is CVE-2026-54097? CVE-2026-54097 is a high-severity security vulnerability in github.com/filebrowser/filebrowser (go), affecting versions <= 1.11.0. It is fixed in 2.63.6.
2. Which packages are affected by CVE-2026-54097?
   • github.com/filebrowser/filebrowser (go) (versions <= 1.11.0)
   • github.com/filebrowser/filebrowser/v2 (go) (versions <= 2.63.5)
3. Is there a fix for CVE-2026-54097? Yes. CVE-2026-54097 is fixed in 2.63.6. Upgrade to this version or later.
4. Is CVE-2026-54097 exploitable, and should I be worried? Whether CVE-2026-54097 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether CVE-2026-54097 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix CVE-2026-54097? Upgrade github.com/filebrowser/filebrowser/v2 to 2.63.6 or later.