Astro: Unauthenticated path override in the @astrojs/vercel ISR function
Priority HIGH 68CWE-441Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-862.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00384 32nd percentileScored 2026-11-07
Fix Fixed astro (withastro): 11.0.3@astrojs/vercel (npm): 11.0.3
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| withastro | astro | 10.0.3 to before 11.0.3 | 11.0.3 | Patch available | CNA |
| — | @astrojs/vercel (npm) | 10.0.3 to before 11.0.3 | 11.0.3 | Patch available | GHSA-x27w-589x-frm2 |
- astro Vendorwithastro Affected 10.0.3 to before 11.0.3 Fixed in 11.0.3 Patch available CNA
- @astrojs/vercel (npm) Vendor— Affected 10.0.3 to before 11.0.3 Fixed in 11.0.3 Patch available GHSA-x27w-589x-frm2
Remediation
- Fix · CNA astro (withastro) Fixed in 11.0.3
- Fix · GHSA-x27w-589x-frm2 @astrojs/vercel (npm) Fixed in 11.0.3 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-73424
- 2026-10-03 Alias added: GHSA-x27w-589x-frm2
References
Other 8
- https://github.com/withastro/astro/security/advisories/GHSA-x27w-589x-frm2
- https://github.com/withastro/astro/pull/17370
- https://github.com/withastro/astro/commit/3a43cf0f3690a8e33cb30109bc5165611cf38fcd
- https://github.com/withastro/astro/releases/tag/@astrojs/[email protected]
- https://github.com/withastro/astro/security/advisories/GHSA-mr6q-rp88-fx84
- https://github.com/withastro/astro/pull/16079
- https://github.com/withastro/astro/commit/aa266364fe9e105317b66e218fe04567307fb57f
- https://github.com/withastro/astro
More withastro vulnerabilities
- TI-2026-26147 Astro: Unauthenticated Path Override via `x-astro-path` / `x_astro_path` CVSS 3.1CRITICAL 9.1
- TI-2026-42600 Astro 6.4.7 Authorization Bypass via Decode Iteration Limit and Rewrite Path Canonicalization Mismatch CVSS 3.1HIGH 8.2
- TI-2024-37142 Server source code is exposed to the public if sourcemaps are enabled CVSS 4.0HIGH 7.8
- TI-2025-35987 Astro Cloudflare adapter is vulnerable to Server-Side Request Forgery via /_image endpoint CVSS 3.1HIGH 7.2
- TI-2025-34958 Unauthorized third-party images in Astro’s _image endpoint CVSS 4.0MEDIUM 6.9
- TI-2025-39915 Server-side request forgery in withastro astro CVSS 3.1MEDIUM 6.5
Sources
- CVE-2026-73424 · CVE Program
- CVE-2026-73424 · NVD
- FIRST EPSS
- GHSA-x27w-589x-frm2 · GitHub Advisory Database · CC BY 4.0
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