CVE-2026-73423

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

MEDIUM
5.1
CVSS Score
Published: August 12, 2026 at 08:35 PM UTC
Updated: October 24, 2026 at 03:10 PM UTC
1 product affected across 1 vendorAstro

Using astro by withastro?

Get instant alerts when new vulnerabilities affect astro - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM5.1
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

>= 7.0.0, < 7.0.6
Affected range stops below 7.0.6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.1MEDIUMGitHub_M
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-352

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card