# CVE-2026-49353: decolua 9router authentication bypass via Host header spoofing

Source: https://junglewise.ai/threats/cve-2026-49353-decolua-9router-authentication-bypass-via-host-header-spoofing  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-15. Updated: 2026-07-15  
License: CC BY 4.0 with a link back

CVE-2026-49353 · Severity: high · CVSS 7.5 · Published 2026-07-15

9Router, an AI-powered router and token management tool, contains a security flaw in how it verifies local access. The system attempts to restrict sensitive administrative and plugin interfaces to local users only, but it relies on easily faked web headers rather than actual network addresses. If the router is used behind a proxy or tunnel, an attacker can bypass these restrictions to interact with internal processes, potentially leading to unauthorized command execution on the host machine.

Technologies: [9router (npm)](https://junglewise.ai/threats/technologies/9router). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-49353 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-49353 being exploited in the wild.

**How severe is CVE-2026-49353?** High severity, with a CVSS score of 7.5, published 15 July 2026.

**Which products and versions are affected?** 9router (npm) <= 0.4.55, SEMVER:introduced=0,last_affected=0.4.55.

**Is there a fix for CVE-2026-49353?** A patch was published on 2026-05-15: Version 0.4.46 released with initial hardening. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-49353 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-49353?** Check whether you run 9router (npm) 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 exists in the isLocalRequest() function within src/dashboardGuard.js, which validates 'local' requests by checking if the Host and Origin headers match loopback addresses (e.g., localhost, 127.0.0.1). Because these headers are attacker-controlled when the application is deployed behind a reverse proxy or tunnel (such as Cloudflare Tunnel or Tailscale), the local-only gate can be bypassed. While a second factor (CLI token) is required, this token is a deterministic HMAC of the machine ID, which may be predictable in cloud environments. Successful exploitation allows an attacker to reach /api/mcp/* and other sensitive routes, enabling interaction with child process stdin (node, python, etc.) and potentially achieving Remote Code Execution (RCE). This is an incomplete fix for a previous vulnerability (CVE-2026-46339).

## Affected products

- decolua 9router <= 0.4.55

## Identifiers

- CVE-2026-49353
- GHSA-6g2f-w7g3-77vf

## Timeline

- 2026-05-15: patched: Version 0.4.46 released with initial hardening.
- 2026-06-13: advisory: GHSA-6g2f-w7g3-77vf published detailing the incomplete fix.
- 2026-07-15: disclosed: CVE-2026-49353 published to NVD.

## References

- [https://github.com/decolua/9router/commit/5e1c1261368e06dced1cbc650684561b2c8844db](https://github.com/decolua/9router/commit/5e1c1261368e06dced1cbc650684561b2c8844db)
- [https://github.com/decolua/9router/commit/bb86808582067e4fc6f004508a919efb9970d1d5](https://github.com/decolua/9router/commit/bb86808582067e4fc6f004508a919efb9970d1d5)
- [https://github.com/decolua/9router/releases/tag/v0.4.46](https://github.com/decolua/9router/releases/tag/v0.4.46)
- [https://github.com/decolua/9router/security/advisories/GHSA-6g2f-w7g3-77vf](https://github.com/decolua/9router/security/advisories/GHSA-6g2f-w7g3-77vf)

## Related threats

- [9Router has a Login Brute-Force Lockout Bypass via Spoofable X-9r-Real-Ip Header](https://junglewise.ai/threats/cve-2026-56682-9router-login-brute-force-lockout-bypass-via-spoofable-header)
- [9Router has an Authentication Bypass in Public LLM API via Spoofable X-9r-Real-Ip Header](https://junglewise.ai/threats/cve-2026-56681-9router-authentication-bypass-in-public-llm-api-via-spoofable-x)
- [9Router unauthenticated server-side request forgery in OIDC test endpoint](https://junglewise.ai/threats/cve-2026-56677-9router-unauthenticated-server-side-request-forgery-in-oidc-test)
- [decolua 9Router mass assignment in /api/settings](https://junglewise.ai/threats/cve-2026-56679-decolua-9router-mass-assignment-in-api-settings)
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