CVE-2026-34528
HIGHCVE-2026-34528 is a high-severity (CVSS 8.1) Improper Privilege Management vulnerability in github.com/filebrowser/filebrowser/v2. O3 Security confirms whether CVE-2026-34528 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
File Browser's Signup Grants Execution Permissions When Default Permissions Includes Execution
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 version 2.62.2, the signupHandler in File Browser applies default user permissions via d.settings.Defaults.Apply(user), then strips only Admin. The Execute permission and Commands list from the default user template are not stripped. When an administrator has enabled signup, server-side execution, and set Execute=true in the default user template, any unauthenticated user who self-registers inherits shell execution capabilities and can run arbitrary commands on the server. This issue has been patched in version 2.62.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/filebrowser/filebrowser/v2 | all versions | 2.62.2 |
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 2.62.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34528 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-2026-34528 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-2026-34528. 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-2026-34528 in your dependencies?
O3 detects CVE-2026-34528 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.