CVE-2026-49353: 9router has an Incomplete Fix: Local-Only Access Gate Bypass in 9router via Host Header SpoofING
Affects 9routerSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 7.5 High.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 15 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| npm9router | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Recommended mitigations include: (1) modifying the local-only access gate to verify the actual source IP address (e.g., using request.ip or request.socket.remoteAddress) rather than trusting Host and Origin headers; (2) replacing the deterministic CLI token with a non-deterministic, randomly generated token persisted on first run; and (3) binding MCP routes to the loopback interface at the network layer to enforce local-only access. Users should monitor vendor advisories for official fixes and apply them once available.
Description
9Router is an AI router & token saver. In 0.4.45 and earlier, 9Router's src/dashboardGuard.js local-only access gate used Host and Origin headers in isLocalRequest() to protect /api/mcp/*, /api/tunnel/*, and /api/cli-tools/*, allowing header spoofing in reverse proxy or tunnel deployments to reach MCP child process stdin paths.
References
- github.com/decolua/9router/security/advisories/GHSA-6g2f-w7g3-77vf (opens in a new tab)
- github.com/decolua/9router/commit/5e1c1261368e06dced1cbc650684561b2c8844db (opens in a new tab)
- github.com/decolua/9router/commit/bb86808582067e4fc6f004508a919efb9970d1d5 (opens in a new tab)
- github.com/decolua/9router/releases/tag/v0.4.46 (opens in a new tab)