# CVE-2026-73424: Astro: Unauthenticated path override in the @astrojs/vercel ISR function

> Unauthenticated attackers can bypass Vercel edge path rules to access protected routes via the ISR function in the Astro Vercel adapter.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Aug 2026
- **Updated:** 18 Aug 2026
- **Also known as:** GHSA-x27w-589x-frm2

## What is CVE-2026-73424?

CVE-2026-73424 is a medium-severity missing authorization vulnerability in withastro astro, published on 17 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Astro is a web framework for content-driven websites. From 10.0.3 until 11.0.3, the Astro Vercel adapter in packages/integrations/vercel/src/serverless/entrypoint.ts accepts x_astro_path for the public /_isr function based only on the x-vercel-isr header, allowing unauthenticated GET requests to render routes protected only by Vercel edge path rules or split edge middleware. This issue is fixed in 11.0.3.

Weakness: CWE-862 (Missing Authorization), CWE-441 (Unintended Proxy or Intermediary)

## Which versions are affected by CVE-2026-73424?

2 open source packages ship an affected version, including @astrojs/vercel.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@astrojs/vercel` | npm | From 10.0.3 | 11.0.3 |
| `@astrojs/vercel` | npm | From 10.0.3 | 11.0.3 |

## How do I fix CVE-2026-73424?

Upgrade @astrojs/vercel to 11.0.3 or later.

## Is CVE-2026-73424 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73424 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-73424 and fix it if it is affected.

What it is: CVE-2026-73424 is a medium-severity missing authorization vulnerability in withastro astro, published on 17 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73424 exists.

Affected packages and fixed versions:
- @astrojs/vercel (npm): affected from 10.0.3; fixed in 11.0.3
- @astrojs/vercel (npm): affected from 10.0.3; fixed in 11.0.3

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-73424/ (Markdown: https://insights.sbomify.com/CVE-2026-73424/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73424
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73424
- OSV: https://osv.dev/vulnerability/CVE-2026-73424

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-73424/
Summaries are generated and may contain mistakes; the official description above is the record.