Medium severity · published Aug 12, 2026
CVE-2026-73423
Astro: composable `astro/hono` pipeline bypasses `security.checkOrigin` when `middleware()` is absent or misordered
5.1
CVSS
0.3%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 18% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AS
astro · withastro
>= 7.0.0, < 7.0.6 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-73423
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-73423
github.com
https://github.com/withastro/astro/commit/0b30b35f864310bee8485c952d1877e82e2b9b1a
github.com
https://github.com/withastro/astro/pull/17250
github.com
https://github.com/withastro/astro/releases/tag/astro@7.0.6
github.com
https://github.com/withastro/astro/security/advisories/GHSA-8mv7-9c27-98vc
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