Summary
@astrojs/node: Backslash-prefixed paths not recognized as internal by trailing-slash redirect
Workarounds
Use the default trailingSlash: 'ignore' setting, which does not issue trailing-slash redirects in the static file handler.
References
Impact
With trailingSlash: 'always' configured, the @astrojs/node standalone server's static file handler appends a trailing slash to request paths and issues a 301 redirect. Paths beginning with /\ (slash-backslash) were not recognized as internal paths, so the handler would echo the raw path back in the Location header. Because browsers treat \ as / per the WHATWG URL specification, the resulting redirect could resolve to an external host.
Preconditions:
trailingSlash: 'always'must be set (non-default; the default is'ignore')- The request path must not have a file extension in its final segment
- An attacker must deliver the crafted link to a user
Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites. Typical impact: phishing and credential harvesting via a trusted domain.
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 by treating backslash-prefixed paths the same as //-prefixed paths in isInternalPath(), so they are no longer rewritten with a trailing slash.
Frequently Asked Questions
- What is CVE-2026-59730? CVE-2026-59730 is a low-severity open redirect vulnerability in @astrojs/node (npm), affecting versions >= 8.1.0, < 11.0.2. It is fixed in 11.0.2. Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites.
- Which versions of @astrojs/node are affected by CVE-2026-59730? @astrojs/node (npm) versions >= 8.1.0, < 11.0.2 is affected.
- Is there a fix for CVE-2026-59730? Yes. CVE-2026-59730 is fixed in 11.0.2. Upgrade to this version or later.
- Is CVE-2026-59730 exploitable, and should I be worried? Whether CVE-2026-59730 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-2026-59730 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-2026-59730? Upgrade
@astrojs/nodeto 11.0.2 or later.