Summary
Astro: Malformed port in the Host header can crash the Node adapter
In the Astro Node adapter, a request whose Host header contains a malformed port (for example example.com:65536 or example.com:8080:8080) produced an invalid request URL. The fallback intended to recover from an unparseable URL reused the same malformed host, so it failed again and raised an uncaught TypeError: Invalid URL while the request was being built, before any route ran.
Affected versions
@astrojs/node <= 11.1.2.
Workarounds
Upgrade to @astrojs/node 11.1.3 or later. Deployments that terminate malformed Host headers at a reverse proxy or CDN are not reachable through this path.
Credits
Reported by @Celggar.
Impact
The effect depends on the adapter configuration:
- Default configuration (
standalone): the request returns500 Internal Server Errorand the server continues running. - With the opt-in
staticHeaders: trueoption: the throw reaches a synchronous HTTP handler that does not catch it, becoming anuncaughtExceptionthat terminates the process.
This is an availability-only issue. It does not expose data or allow code execution. Triggering it requires sending a hand-crafted Host header, and many proxies and CDNs reject malformed hosts before they reach the origin.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Fixed in @astrojs/node 11.1.3. When the incoming host cannot be parsed, the request URL now degrades to a host the server controls, so the request is handled instead of throwing. Hosts carrying more than a single hostname:port pair are also rejected during host validation.
Frequently Asked Questions
- What is CVE-2026-102984? CVE-2026-102984 is a high-severity security vulnerability in @astrojs/node (npm), affecting versions <= 11.1.2. It is fixed in 11.1.3.
- Which versions of @astrojs/node are affected by CVE-2026-102984? @astrojs/node (npm) versions <= 11.1.2 is affected.
- Is there a fix for CVE-2026-102984? Yes. CVE-2026-102984 is fixed in 11.1.3. Upgrade to this version or later.
- Is CVE-2026-102984 exploitable, and should I be worried? Whether CVE-2026-102984 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-102984 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-102984? Upgrade
@astrojs/nodeto 11.1.3 or later.