Astro 6.4.7 Authorization Bypass via Decode Iteration Limit and Rewrite Path Canonicalization Mismatch
Priority HIGH 75CWE-647Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
Astro is a web framework for content-driven websites. Version 6.4.7 performs authorization decisions on a partially decoded pathname after reaching the iterative URL decoder limit, while later rewrite route matching performs an additional decodeURI() operation and can resolve the request to a protected route. This issue is fixed in version 6.4.8.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00331 26th percentileScored 2026-11-07
Fix Fixed astro (withastro): 6.4.8astro (npm): 6.4.8
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 | 6.4.7 to before 6.4.8 | 6.4.8 | Patch available | CNA |
| — | astro (npm) | 6.4.7 to before 6.4.8 | 6.4.8 | Patch available | GHSA-vj59-8hwv-xxmv |
- astro Vendorwithastro Affected 6.4.7 to before 6.4.8 Fixed in 6.4.8 Patch available CNA
- astro (npm) Vendor— Affected 6.4.7 to before 6.4.8 Fixed in 6.4.8 Patch available GHSA-vj59-8hwv-xxmv
Remediation
- Fix · CNA astro (withastro) Fixed in 6.4.8
- Fix · GHSA-vj59-8hwv-xxmv astro (npm) Fixed in 6.4.8 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-59731
- 2026-10-03 Alias added: GHSA-vj59-8hwv-xxmv
References
Other 5
- https://github.com/withastro/astro/security/advisories/GHSA-vj59-8hwv-xxmv
- https://github.com/withastro/astro/pull/17109
- https://github.com/withastro/astro/commit/27c80ea92248993e5fce94b2c26d87d611ab6785
- https://github.com/withastro/astro/releases/tag/[email protected]
- 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-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-2026-51542 Astro: Unauthenticated path override in the @astrojs/vercel ISR function CVSS 3.1MEDIUM 6.5
- TI-2025-39915 Server-side request forgery in withastro astro CVSS 3.1MEDIUM 6.5
Sources
- CVE-2026-59731 · CVE Program
- CVE-2026-59731 · NVD
- FIRST EPSS
- GHSA-vj59-8hwv-xxmv · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences