@astrojs/node: Backslash-prefixed paths not recognized as internal by trailing-slash redirect
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Active
- Attack complexity
- High
- Attack requirements
- None
- Impact type
- Spoofing
- Confidentiality · integrity · availability
- None · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-601.
Summary
Astro is a web framework for content-driven websites. In versions 8.1.0 through 11.0.1, when trailingSlash: 'always' is configured, the @astrojs/node standalone server's static file handler appends a trailing slash to request paths and issues a 301 redirect. Paths beginning with /\ (slash-backslash) were not recognized as internal paths, so the handler would echo the raw path back in the Location header. Because browsers treat \ as / per the WHATWG URL specification, the resulting redirect could resolve to an external host. Preconditions for exploitation: trailingSlash: 'always' must be set (non-default; the default is 'ignore'), the request path must not have a file extension in its final segment, and an attacker must deliver the crafted link to a user. This issue has been fixed in version 11.0.2.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- 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 | 8.1.0 to before 11.0.2 | 11.0.2 | Patch available | CNA |
| — | @astrojs/node (npm) | 8.1.0 to before 11.0.2 | 11.0.2 | Patch available | GHSA-r557-wffq-wvrc |
- astro Vendorwithastro Affected 8.1.0 to before 11.0.2 Fixed in 11.0.2 Patch available CNA
- @astrojs/node (npm) Vendor— Affected 8.1.0 to before 11.0.2 Fixed in 11.0.2 Patch available GHSA-r557-wffq-wvrc
Remediation
- Fix · CNA astro (withastro) Fixed in 11.0.2
- Fix · GHSA-r557-wffq-wvrc @astrojs/node (npm) Fixed in 11.0.2 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-59730
- 2026-10-03 Alias added: GHSA-r557-wffq-wvrc
References
Other 5
- https://github.com/withastro/astro/security/advisories/GHSA-r557-wffq-wvrc
- https://github.com/withastro/astro/pull/17252
- https://github.com/withastro/astro/commit/eb6f97e391ee587747e37609c255c7cd4b9cce3c
- https://github.com/withastro/astro/releases/tag/@astrojs/[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-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-2026-51542 Astro: Unauthenticated path override in the @astrojs/vercel ISR function CVSS 3.1MEDIUM 6.5
Sources
- CVE-2026-59730 · CVE Program
- CVE-2026-59730 · NVD
- FIRST EPSS
- GHSA-r557-wffq-wvrc · GitHub Advisory Database · CC BY 4.0
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