How severe is GHSA-w789-49fc-v8hr?

No CVSS score has been assigned to GHSA-w789-49fc-v8hr yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-w789-49fc-v8hr?

GHSA-w789-49fc-v8hr affects the following packages: terriajs-server (npm). Ecosystems affected: npm.

How do I fix GHSA-w789-49fc-v8hr?

Update terriajs-server to 4.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w789-49fc-v8hr is resolved across your whole dependency graph.

How do I detect GHSA-w789-49fc-v8hr in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for terriajs-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-w789-49fc-v8hr if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-w789-49fc-v8hr?

O3 pinpoints whether GHSA-w789-49fc-v8hr is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-w789-49fc-v8hr actively exploited in the wild?

No public exploit code has been indexed for GHSA-w789-49fc-v8hr yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What type of vulnerability is GHSA-w789-49fc-v8hr?

GHSA-w789-49fc-v8hr is classified as Improper Input Validation (CWE-20), Server-Side Request Forgery (SSRF) (CWE-918). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-w789-49fc-v8hr published, and has it been updated?

GHSA-w789-49fc-v8hr was published on February 26, 2026 and was last updated on February 26, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

GHSA-w789-49fc-v8hr

GHSA-w789-49fc-v8hr is a Improper Input Validation vulnerability in terriajs-server. O3 Security confirms whether GHSA-w789-49fc-v8hr is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

TerriaJS-Server has a domain validation bypass vulnerability in its proxy allowlist

Also known asCVE-2026-27818

Published

Feb 26, 2026

Updated

Feb 26, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Blast Radius

1 pkg affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

terriajs-servernpm

1Kdownloads / week

Description

Impact

A validation bug allows an attacker to proxy domains not explicitly allowed in the proxyableDomains configuration.

The validation only checks if a hostname ended with an allowed domain. This meant:

If example.com is allowed in proxyableDomains:

✅ example.com is allowed (correct)
✅ api.example.com is allowed (correct)
⚠️ maliciousexample.com is allowed (incorrect)

An attacker could register maliciousexample.com and proxy content through terriajs-server, bypassing proxy restrictions.

Patches

All versions up to 4.0.2 are affected. Upgrade to 4.0.3 to address the vulnerability.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`terriajs-server`	all versions	4.0.3

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for terriajs-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update terriajs-server to 4.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w789-49fc-v8hr is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-w789-49fc-v8hr is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-w789-49fc-v8hr. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact A validation bug allows an attacker to proxy domains not explicitly allowed in the `proxyableDomains` configuration. The validation only checks if a hostname _ended_ with an allowed domain. This meant: If `example.com` is allowed in `proxyableDomains`: - ✅ example.com is allowed (correct) - ✅ api.example.com is allowed (correct) - ⚠️ maliciousexample.com is allowed (incorrect) An attacker could register maliciousexample.com and proxy content through `terriajs-server`, bypassing proxy restrictions. ### Patches All versions up to 4.0.2 are affected. Upgrade to 4.0.3 to address th

O3 Security · Impact-Aware SCA

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