CVE-2026-27818: TerriaJS-Server Domain Validation Bypass Vulnerability
Summary
CVE-2026-27818: TerriaJS-Server has a domain validation bypass vulnerability in its proxy allowlist. Affects terriajs-server versions < 4.0.3. Fixed in 4.0.3. How to fix ↓
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Background
TerriaJS-Server is an open-source server designed to facilitate the serving of geospatial data and applications. It allows users to proxy requests to various domains, enabling seamless integration of diverse data sources. However, the server's proxy functionality is susceptible to a domain validation bypass vulnerability, which can lead to unauthorized access to restricted domains.
Vulnerability Detail
The vulnerability arises from a validation bug in the proxy allowlist configuration of TerriaJS-Server. The server only checks if a hostname ends with an allowed domain, which can be exploited by an attacker. For instance, if 'example.com' is allowed, an attacker could register 'maliciousexample.com' and successfully proxy content through the server, bypassing intended restrictions. This flaw can lead to unauthorized data access and potential security breaches.
How To Fix
Minimum fixed version
4.0.3
This is the first release that contains the fix.
npm install terriajs-server@4.0.3Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, users can manually review and restrict the domains listed in the 'proxyableDomains' configuration to ensure that only trusted domains are included. However, upgrading to the patched version is the recommended solution.
Conclusion
The domain validation bypass vulnerability in TerriaJS-Server poses significant security risks by allowing unauthorized access to proxied domains. Users are strongly advised to upgrade to version 4.0.3 to mitigate this risk and ensure the integrity of their applications.
See every vulnerability recorded for terriajs-server →
FAQ
The CVSS score of this vulnerability is 8.7, indicating a high severity level.
All versions up to 4.0.2 are affected by this vulnerability.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without requiring any signup.
If immediate upgrading is not possible, ensure to restrict the domains in the 'proxyableDomains' configuration to trusted sources as a temporary measure.
Vulert is a tool that monitors and alerts in real-time for open-source vulnerabilities using just the package-lock.json file. More information can be found at https://vulert.com.
References
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