# CVE-2026-86543: knowns management API authentication bypass

Source: https://junglewise.ai/threats/cve-2026-86543-knowns-management-api-authentication-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-07. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-86543 · Severity: critical · CVSS 9.8 · Published 2026-09-07

knowns is a tool for creating secure tunnels and managing network access. Versions before 0.30.0 expose the management API without any authentication on all network interfaces by default, allowing anyone with network access to start tunnels and republish the API publicly. An attacker can abuse this to gain unauthorized control over the application and potentially redirect traffic or compromise connected services.

Technologies: [Knowns-Dev Knowns](https://junglewise.ai/threats/technologies/knowns). Vendors: [Knowns-Dev](https://junglewise.ai/threats/vendors/knowns-dev).

## Quick answers

**Is CVE-2026-86543 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-86543 being exploited in the wild.

**How severe is CVE-2026-86543?** Critical severity, with a CVSS score of 9.8, published 7 September 2026.

**Which products and versions are affected?** Knowns-Dev Knowns before 0.30.0.

**Is there a fix for CVE-2026-86543?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-86543 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-86543?** Check whether you run Knowns-Dev Knowns at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an authentication bypass in the management API service. The management API endpoints, including /api/tunnel/start, are served without authentication checks on fresh installations (no password configured by default). The AuthManager component exists but is not enforced on API routes before version 0.30.0. An attacker with network access to the management API can directly invoke unauthenticated endpoints to provision public tunnels and republish the API at a publicly accessible address. The fix is available in version 0.30.0 and later, which enforces authentication on the management API by default.

## Affected products

- knowns-dev knowns before 0.30.0

## Timeline

- 2026-09-07: disclosed

## References

- [https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/cli/browser.go](https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/cli/browser.go)
- [https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/server/auth.go](https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/server/auth.go)

## Related threats

- [Knowns path traversal in workspace browse endpoint](https://junglewise.ai/threats/cve-2026-88940-knowns-path-traversal-in-workspace-browse-endpoint)
- [knowns path traversal in code.find MCP tool](https://junglewise.ai/threats/cve-2026-88938-knowns-path-traversal-in-code-find-mcp-tool)
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- [knowns path traversal in Document API](https://junglewise.ai/threats/cve-2026-86775-knowns-path-traversal-in-document-api)