Is CVE-2026-55638 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-55638 being exploited in the wild.

How severe is CVE-2026-55638?

High severity, with a CVSS score of 8.6, published 10 July 2026.

Which products and versions are affected?

9router (npm) < 0.5.2, SEMVER:introduced=0,fixed=0.5.2.

Is there a fix for CVE-2026-55638?

Yes. 9router (npm): upgrade to 0.5.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-55638 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-55638?

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.

CVE-2026-55638: decolua 9router auth bypass via /codex rewrite

Q: Which products and versions are affected?

9router (npm) < 0.5.2, SEMVER:introduced=0,fixed=0.5.2.

Q: Is there a fix for CVE-2026-55638?

Yes. 9router (npm): upgrade to 0.5.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-55638 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-55638?

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.

CVE-2026-55638 · Severity: high · CVSS 8.6 · Published 2026-07-10

9router is a proxy service that provides an OpenAI/Anthropic-compatible LLM (large language model) interface, designed to be protected by API-key authentication. However, a flaw in how the application handles URL rewrites allows unauthenticated attackers to bypass the API-key check by sending requests to the `/codex/*` endpoint instead of the protected `/api/v1/*` endpoint. This allows attackers to use the service operator's credentials to make LLM API calls, consume their provider credits, and incur unexpected billing charges.

Technologies: 9router (npm). Vendors: npm.

Quick answers

Is CVE-2026-55638 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-55638 being exploited in the wild.
How severe is CVE-2026-55638?: High severity, with a CVSS score of 8.6, published 10 July 2026.
Which products and versions are affected?: 9router (npm) < 0.5.2, SEMVER:introduced=0,fixed=0.5.2.
Is there a fix for CVE-2026-55638?: Yes. 9router (npm): upgrade to 0.5.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-55638 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-55638?: 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.

How to fix

9router (npm): upgrade to 0.5.2 or later
```
npm install 9router@0.5.2
```

Technical details

This is an authorization bypass vulnerability in 9router's Next.js middleware logic. The vulnerability stems from a timing mismatch in the request authorization flow: the middleware in `src/dashboardGuard.js` evaluates whether a request requires an API key based on the original request path before Next.js URL rewrites are applied. The protected prefix list includes `/v1`, `/v1beta`, `/api/v1`, and `/api/v1beta`, but excludes `/codex`. The `next.config.mjs` configuration contains a rewrite rule mapping `/codex/:path*` to `/api/v1/responses`. When an attacker sends a POST request to `/codex/x`, the middleware allows it to pass (because `/codex` is not protected), and the request is then rewritten to `/api/v1/responses` where it is processed by the chat handler using the operator's stored LLM provider API keys. The vulnerability is network-accessible with no authentication required and no user interaction needed. A patch is available in version 0.5.2.

Affected products

decolua 9router < 0.5.2

Identifiers

CVE-2026-55638
GHSA-8gmq-j984-vp4r

Timeline

2026-07-07: disclosed
2026-07-10: patched: patch released in v0.5.2
2026-08-28: advisory

References

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