CVE-2026-463399Router: Unauthenticated Remote Code Execution via unprotected MCP custom plugin routes
- 10.0CriticalCVSS base score
- 2.8%Exploitation in 30 daysEPSS · top 13% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- 1Public exploitsMetasploit, Nuclei and Exploit-DB
Description
9Router is an AI router & token saver. From 0.4.30 until 0.4.37, 9Router's src/proxy.js middleware did not protect /api/cli-tools/* and /api/mcp/*, allowing unauthenticated registration of customPlugins through src/app/api/cli-tools/cowork-settings/route.js and command execution through the MCP bridge. This vulnerability is fixed in 0.4.37.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. The public collections list a Nuclei template for it. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits2
Nuclei templates1 template
- 9Router <= 0.4.36 - Unauthenticated RCE (Nuclei template) (opens in a new tab)
http/cves/2026/CVE-2026-46339.yamlSeverity critical
References tagged exploit1 reference
- https://github.com/decolua/9router/security/advisories/GHSA-fhh6-4qxv-rpqj (opens in a new tab)x_refsource_CONFIRMexploit
Modules, templates and exploits as listed by the Metasploit Framework (BSD-3-Clause), ProjectDiscovery's Nuclei templates (MIT) and the Exploit Database (GPLv2), read once a day. Where the data comes from
Timeline
ID reserved
By GitHub_M
- 2 months later
· 2 months later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Critical10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Deferred | 3.1 | Critical10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 2.8% · top 13% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 10.0.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- npm9routerGHSA-fhh6-4qxv-rpqj (opens in a new tab)
References
References2
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-44808 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-fhh6-4qxv-rpqj (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-46339)Record last updated .