GHSA-ggxq-hp9w-j794
Astro's middleware authentication checks based on url.pathname can be bypassed via url encoded values
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
astronpmDescription
A mismatch exists between how Astro normalizes request paths for routing/rendering and how the application’s middleware reads the path for validation checks. Astro internally applies decodeURI() to determine which route to render, while the middleware uses context.url.pathname without applying the same normalization (decodeURI).
This discrepancy may allow attackers to reach protected routes (e.g., /admin) using encoded path variants that pass routing but bypass validation checks.
/** The main logic to route dev server requests to pages in Astro. */
export async function handleRequest({
pipeline,
routesList,
controller,
incomingRequest,
incomingResponse,
}: HandleRequest) {
const { config, loader } = pipeline;
const origin = `${loader.isHttps() ? 'https' : 'http'}://${
incomingRequest.headers[':authority'] ?? incomingRequest.headers.host
}`;
const url = new URL(origin + incomingRequest.url);
let pathname: string;
if (config.trailingSlash === 'never' && !incomingRequest.url) {
pathname = '';
} else {
// We already have a middleware that checks if there's an incoming URL that has invalid URI, so it's safe
// to not handle the error: packages/astro/src/vite-plugin-astro-server/base.ts
pathname = decodeURI(url.pathname); // here this url is for routing/rendering
}
// Add config.base back to url before passing it to SSR
url.pathname = removeTrailingForwardSlash(config.base) + url.pathname; // this is used for middleware context
Consider an application having the following middleware code:
import { defineMiddleware } from "astro/middleware";
export const onRequest = defineMiddleware(async (context, next) => {
const isAuthed = false; // simulate no auth
if (context.url.pathname === "/admin" && !isAuthed) {
return context.redirect("/");
}
return next();
});
context.url.pathname is validated , if it's equal to /admin the isAuthed property must be true for the next() method to be called. The same example can be found in the official docs https://docs.astro.build/en/guides/authentication/
context.url.pathname returns the raw version which is /%61admin while pathname which is used for routing/rendering /admin, this creates a path normalization mismatch.
By sending the following request, it's possible to bypass the middleware check
GET /%61dmin HTTP/1.1
Host: localhost:3000
Remediation
Ensure middleware context has the same normalized pathname value that Astro uses internally, because any difference could allow it to bypass such checks. In short maybe something like this
pathname = decodeURI(url.pathname);
}
// Add config.base back to url before passing it to SSR
- url.pathname = removeTrailingForwardSlash(config.base) + url.pathname;
+ url.pathname = removeTrailingForwardSlash(config.base) + decodeURI(url.pathname);
Thank you, let @Sudistark know if any more info is needed. Happy to help :)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | astro | all versions | 5.15.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for astro. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update astro to 5.15.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-ggxq-hp9w-j794 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-ggxq-hp9w-j794 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-ggxq-hp9w-j794. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-ggxq-hp9w-j794 in your dependencies?
O3 detects GHSA-ggxq-hp9w-j794 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.