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CVE-2026-63732 decolua CVE debrief

The 9router 0.4.59 version, as detailed in CVE-2026-63732, presents multiple critical vulnerabilities. These include a hardcoded default password (123456) for fresh installations, a mechanism to bypass the LOCAL_ONLY network gate through a spoofed Host header, and the passing of unvalidated arguments to child_process.spawn() during MCP plugin registration. An unauthenticated remote attacker can exploit these vulnerabilities to gain login access with the default credential, access local-only routes by spoofing the Host header, and execute arbitrary code on the host operating system by registering a malicious MCP plugin. This CVE record was published on 2026-07-23T22:16:53.023Z and was last modified on 2026-07-27T17:16:38.963Z.

Vendor
decolua
Product
9router
CVSS
CRITICAL 9.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-23
Original CVE updated
2026-07-28
Advisory published
2026-07-23
Advisory updated
2026-07-28

Who should care

System administrators and security professionals responsible for 9router installations should be aware of CVE-2026-63732. Given the critical severity (CVSS score of 9.4), immediate attention is required to mitigate the risks associated with these vulnerabilities.

Technical summary

CVE-2026-63732 involves a chain of vulnerabilities in 9router version 0.4.59. The vulnerabilities include a hardcoded default password (123456) for new installations, allowing unauthorized access. There's also a bypass mechanism for the LOCAL_ONLY network gate through Host header spoofing. Furthermore, unvalidated arguments are passed to child_process.spawn() when registering MCP plugins, enabling an attacker to execute arbitrary code on the host OS when a malicious plugin's SSE endpoint is triggered.

Defensive priority

High

Recommended defensive actions

  • Update 9router to version 0.4.60 or later to patch the vulnerabilities.
  • Change default passwords for all 9router installations to unique, strong passwords.
  • Implement additional security measures such as network segmentation and monitoring to detect and prevent exploitation attempts.
  • Review and restrict the use of MCP plugins to only those that are necessary and from trusted sources.
  • Enhance network security by configuring the LOCAL_ONLY network gate to properly validate Host headers.

Evidence notes

The CVE record and NVD detail provide information on the vulnerabilities in 9router 0.4.59. Additional details can be found in the source references provided, including advisories from Vulncheck and a GitHub security advisory.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-63732 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-63732

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-63732 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-63732

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.