CVE-2026-32760: File Browser Signup Grants Admin When Default Permissions Include Admin

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.7%, percentile 53: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 53% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes github.com/filebrowser/filebrowser/v2 (Go) <= 2.61.2, fixed in 2.62.0. Check your lockfile, including transitive dependencies.

What it is

File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. In versions 2.61.2 and below, any unauthenticated visitor can register a full administrator account when self-registration (signup = true) is enabled and the default user permissions have perm.admin = true. The signup handler blindly applies all default settings (including Perm.Admin) to the new user without any server-side guard that strips admin from self-registered accounts. The signupHandler is supposed to create unprivileged accounts for new visitors. It contains no explicit user.Perm.Admin = false reset after applying defaults. If an administrator (intentionally or accidentally) configures defaults.perm.admin = true and also enables signup, every account created via the public registration endpoint is an administrator with full control over all files, users, and server settings. This issue has been resolved in version 2.62.0.

From the GitHub advisory

Summary Any unauthenticated visitor can register a full administrator account when self-registration ( signup = true ) is enabled and the default user permissions have perm.admin = true. The signup handler blindly applies all default settings - including Perm.Admin - to the new user without any server-side guard that strips admin from self-registered accounts.

Details

Affected file: http/auth.go

Vulnerable code:

settings.UserDefaults.Apply (settings/defaults.go):

Weakness type: CWE-269, CWE-284.

Product: github.com/filebrowser/filebrowser/v2 (Go) · Assigned by: GitHub_M · Published: 2026-03-19

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.72% probability of exploitation activity in the next 30 days; percentile 53.

Timeline

• 2026-03-16 — GitHub-reviewed advisory GHSA-5gg9-5g7w-hm73 published (critical)
• 2026-03-19 — CVE record published by GitHub_M
• 2026-03-25 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-5gg9-5g7w-hm73 github.com
2. CVE.org record CVE-2026-32760 cve.org
3. NVD entry CVE-2026-32760 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com

Critical Go advisories · Today’s Security Digest