---
id: CVE-2026-86543
title: >-
  knowns versions before 0.30.0 serve the management API without authentication
  on all network interfaces by default, with no password required on fresh
  installations
summary: >-
  knowns versions before 0.30.0 serve the management API without authentication
  on all network interfaces by default, with no password required on fresh
  installations. Attackers can access the unauthenticated /api/tunnel/start
  endpoint to …
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-306
vendor: knowns-dev
product: knowns
affected:
  - knowns < 0.30.0
published: '2026-09-07'
updated: '2026-09-14'
sourceUpdated: '2026-09-14T20:17:01.263'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-86543'
references:
  - url: >-
      https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/cli/browser.go#L193-L200
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/server/auth.go#L80-L86
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/server/routes/tunnel.go#L26-L38
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/knowns-dev/knowns/commit/878a02cb7cc14f0a592fdfda7a520af3cac500fb
    label: disclosure@vulncheck.com
  - url: 'https://github.com/knowns-dev/knowns/releases/tag/v0.30.0'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/knowns-dev/knowns/security/advisories/GHSA-fc85-99vc-9c75
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/knowns-before-0.30.0-unauthenticated-management-api-exposure
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
epss: 0.00856
epssPercentile: 0.5664
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-09-14T19:22:17.717841Z'
ingestedAt: '2026-09-08T15:33:26.980Z'
---

## Overview

knowns versions before 0.30.0 serve the management API without authentication on all network interfaces by default, with no password required on fresh installations. Attackers can access the unauthenticated /api/tunnel/start endpoint to provision a public tunnel and republish the API at a publicly accessible address.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.