CVE-2026-55667
HIGHCVE-2026-55667 is a high-severity (CVSS 8.2) Path Traversal vulnerability in github.com/filebrowser/filebrowser/v2. O3 Security confirms whether CVE-2026-55667 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
File Browser: Out-of-scope file deletion by a Create-only scoped user via symlink-following RemoveAll in upload failure-cleanup
Real-World Exposure
github.com/filebrowser/filebrowser/v2Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to 2.63.16, a scoped, non-admin File Browser user holding only the Create permission can delete arbitrary files outside their scope (other tenants' data, and the application's own database) via the upload failure-cleanup path. ScopedFs.RemoveAll is the one dereferencing operation that skips the symlink guard every other method enforces. The direct-upload handler runs RemoveAll on the user-controlled path during failed-upload cleanup, gated only by Perm.Create. If an escaping directory symlink already exists inside the user's scope, an authenticated create-only user can delete an out-of-scope target, bypassing both the ScopedFs boundary and the Perm.Delete gate. This vulnerability is fixed in 2.63.16.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/filebrowser/filebrowser/v2 | all versions | 2.63.16 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/filebrowser/filebrowser/v2. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/filebrowser/filebrowser/v2 to 2.63.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55667 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-55667 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-55667. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-55667 in your dependencies?
O3 detects CVE-2026-55667 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.