Vulnerability · Published Jul 10, 2026 · Assigned by GitHub_M

CVE-2026-556389router: Unauthenticated LLM proxy access via /codex rewrite authorization bypass

High 8.6

In plain English

A high-severity missing authorization in 9router from decolua. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 6.6% (higher than 94% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.6High

Exploit odds (30 days)6.6%top 6.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

9Router is an AI router & token saver. Prior to 0.5.2, 9router protects /v1, /v1beta, /api/v1, and /api/v1beta in src/dashboardGuard.js but omits /codex before next.config.mjs rewrites /codex/* to /api/v1/responses. A remote unauthenticated attacker can send requests to /codex/* to bypass the API-key gate and cause the server to make upstream provider calls using operator-stored LLM provider credentials. This issue is fixed in version 0.5.2.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	9router	0.5.2	GHSA-8gmq-j984-vp4r

Affected products (as reported)

Vendor	Product	Versions
decolua	9router	< 0.5.2

Weakness: CWE-862, CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

References

https://github.com/decolua/9router/security/advisories/GHSA-8gmq-j984-vp4r x_refsource_CONFIRM
https://github.com/decolua/9router/commit/b282f0554972ea35281520738759d76abcd0b0b3 x_refsource_MISC
https://github.com/decolua/9router/releases/tag/v0.5.2 x_refsource_MISC