# CVE-2026-73423: Astro: composable `astro/hono` pipeline bypasses `security.checkOrigin` when `middleware()` is absent or misordered

> Attackers can perform cross-site request forgery against Astro actions and pages if the security middleware is misordered or omitted, allowing state-changing requests.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 12 Aug 2026
- **Updated:** 13 Aug 2026
- **Also known as:** GHSA-8mv7-9c27-98vc

## What is CVE-2026-73423?

CVE-2026-73423 is a medium-severity vulnerability in withastro astro, published on 12 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Astro is a web framework for content-driven websites. From 7.0.0 until 7.0.6, the composable astro/hono pipeline installs security.checkOrigin only through the middleware() primitive, while actions() and pages() can dispatch to user code independently. Mounting actions() before middleware(), as in the examples/advanced-routing example and Cloudflare Hono documentation, allows cross-origin form-encoded action requests to execute before the origin check, and using pages() without middleware() drops the check for on-demand endpoints and pages. The flaw enables blind write-only cross-site request forgery using the victim's cookies against ActionHandler.handle and PagesHandler.handleWithErrorFallback when manifest.checkOrigin is enabled; the attacker can trigger a state-mutating action or endpoint handler but cannot read the cross-origin response. The default non-composable astro() pipeline is not affected. This issue is fixed in version 7.0.6.

Weakness: CWE-352 (Cross-Site Request Forgery)

## Which versions are affected by CVE-2026-73423?

2 open source packages ship an affected version, including astro.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `astro` | npm | From 7.0.0 | 7.0.6 |
| `astro` | npm | From 7.0.0 | 7.0.6 |

## How do I fix CVE-2026-73423?

Upgrade astro to 7.0.6 or later.

## Is CVE-2026-73423 being exploited?

There is no known exploitation of CVE-2026-73423 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-73423 and fix it if it is affected.

What it is: CVE-2026-73423 is a medium-severity vulnerability in withastro astro, published on 12 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-73423 in the wild and no public exploit code.

Affected packages and fixed versions:
- astro (npm): affected from 7.0.0; fixed in 7.0.6
- astro (npm): affected from 7.0.0; fixed in 7.0.6

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-2026-73423/ (Markdown: https://insights.sbomify.com/CVE-2026-73423/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73423
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73423
- OSV: https://osv.dev/vulnerability/CVE-2026-73423

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-73423/
Summaries are generated and may contain mistakes; the official description above is the record.