# CVE-2026-23744: REC in MCPJam inspector due to HTTP Endpoint exposes

- Exploited (CISA KEV): no
- Published: 2026-01-16
- CVSS: 9.8 CRITICAL (v3.1)
- EPSS: 67.5% (99th percentile)
- CWE: CWE-306

MCPJam inspector is the local-first development platform for MCP servers. Versions 1.4.2 and earlier are vulnerable to remote code execution (RCE) vulnerability, which allows an attacker to send a crafted HTTP request that triggers the installation of an MCP server, leading to RCE. Since MCPJam inspector by default listens on 0.0.0.0 instead of 127.0.0.1, an attacker can trigger the RCE remotely via a simple HTTP request. Version 1.4.3 contains a patch.

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Blocks by default | 2026-04-07 | 81 |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2026-07-07 | 172 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### Cloudflare

- 2026-04-07 · new · rule 1177993d53a1467997002b44d46229eb · default Block
  > MCP Server - Remote Code Execution - CVE:CVE-2026-23744. Previous action: Log. New action: Block. This is a new detection.
  Source: https://developers.cloudflare.com/changelog/post/2026-04-07-waf-release/

### F5

- 2026-07-07 · new · rule 200103681
  > Added: signature 200103681 "MCPJam Inspector Remote Code Execution" (Command Execution, risk High), systems: Other Web Server. References: CVE-2026-23744.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog

## Our test (measured)

- OWASP Core Rule Set 4.25.0, paranoia level 1, anomaly threshold 5, default CRS settings: passed (0 of 1 requests blocked), template CVE-2026-23744, 2026-11-02
- OWASP Core Rule Set 4.25.0, paranoia level 2, anomaly threshold 5, default CRS settings: passed (0 of 1 requests blocked), template CVE-2026-23744, 2026-11-02

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2026-23744 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2026-23744