S4E just found a high-severity finding from top 10 tcp port service scan
PlatformPlansPartners
Resources
ToolsBlogDocs
Sign Up →
high·Product Based Web Vulnerabilities·Updated May 6, 2026

CVE-2026-25545 Scanner

CVE-2026-25545 Scanner - Server-Side Request Forgery (SSRF) vulnerability in Astro SSR

Est. Time~1 minutes
Scan TypeSingle Scan
Targetsurl
CostFree
3.3k
Times Used
continuous scan runs
5.8k
Continuously Checked
assets under CS
0
Vulnerabilities Found
confirmed findings
References
CVECVE-2026-25545
6.9
CVSSmedium
Exploitable remotely over the internet · no authentication required.

Astro is a web framework. Prior to version 9.5.4, Server-Side Rendered pages that return an error with a prerendered custom error page (eg. `404.astro` or `500.astro`) are vulnerable to SSRF. If the `Host:` header is changed to an attacker's server, it will be fetched on `/500.html` and they can redirect this to any internal URL to read the response body through the first request. An attacker who can access the application without `Host:` header validation (eg. through finding the origin IP behind a proxy, or just by default) can fetch their own server to redirect to any internal IP. With this they can fetch cloud metadata IPs and interact with services in the internal network or localhost. For this to be vulnerable, a common feature needs to be used, with direct access to the server (no proxies). Version 9.5.4 fixes the issue.

Attack Vector
Network
Privileges Req.
None
User Interaction
None
Affected
astroby withastro
< 9.5.4
Updated Aug 22, 2026View on NVD →
Detail

Astro SSR is a static site generator designed for modern web applications, enabling developers to create fast and optimized static content. It is utilized by web developers and companies for building performant websites that require server-side rendering. Offering seamless integrations with modern JavaScript frameworks, Astro is ideal for static site deployments and complex web applications. Companies focusing on high-performance web solutions often choose Astro for its flexibility and ease of use. Industries including e-commerce, tech startups, and digital agencies leverage Astro to maintain agility in web development. Its wide adoption is due to its ability to handle large-scale content effectively with minimal load times.

The vulnerability in Astro SSR, identified as Server-Side Request Forgery (SSRF), occurs due to improper Host header validation on error page rendering. This SSRF vulnerability can be exploited to redirect requests to internal resources, which poses significant security risks. Attackers can leverage this vulnerability to access sensitive endpoints like cloud metadata services unauthorisedly. By redirecting requests through the server, malicious entities can exploit backend resources without detection. The vulnerability is severe due to the low level of skill required to execute an exploit and the potential impact on confidentiality. Addressing this vulnerability promptly is crucial to maintaining infrastructure security.

Technical details about this SSRF vulnerability involve improper validation of the Host header in error page rendering, which facilitates full-read exploitation. This flaw allows attackers to bypass normal access controls and interact with internal services through crafted requests. The risk is amplified by the fact that an attacker can reach environment files, metadata endpoints, and any host accessible by the server. Details indicate that patching the systems by upgrading to secure versions, which involve error handling changes, mitigates the risk. This vulnerability impacts environments where Astro is employed for backend and API integrations. Ensuring the validation of incoming host headers is essential to neutralize this attack vector.

Exploitation of this vulnerability can have dire consequences, including unauthorized access to internal services and sensitive data exposure. Attackers could leverage this flaw to gain insights into cloud-based environments, potentially breaching security perimeters. Unauthorized access to metadata endpoints might allow attackers to execute subsequent attacks on cloud infrastructure. The compromise of environment files could lead to the exposure of sensitive configuration data, thereby escalating the scope of potential breaches. Overarching effects encompass data leakage, unauthorized service access, and potential full-scale network compromise. Mitigating such risks requires immediate attention and strategic remediation.

REFERENCES

Solution Advice
  • Upgrade Astro to version 5.17.3 or later, and @astrojs/node to version 9.5.4 or later.
  • Implement strict Host header validation to prevent unauthorized requests.
  • Deploy network monitoring to detect and log anomalous activity related to potential SSRF attacks.
  • Regularly audit and patch systems to prevent exploitation of known vulnerabilities.
  • Separate sensitive services from those exposed to public networks to mitigate impact.

Get AI-powered remediation steps tailored to your asset.

Try AI Solutions →

Check your infrastructure.
Right now.

11,000+ scanners. Free to start. No credit card required.