Vulnerability · Published Feb 26, 2026 · Assigned by GitHub_M

CVE-2026-27818TerriaJS-Server has a domain validation bypass vulnerability in its proxy allowlist

High 8.7

In plain English

A high-severity improper input validation in terriajs-server from TerriaJS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.7High

Exploit odds (30 days)0.3%top 79.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

TerriaJS-Server is a NodeJS Express server for TerriaJS, a library for building web-based geospatial data explorers. A validation bug in versions prior to 4.0.3 allows an attacker to proxy domains not explicitly allowed in the `proxyableDomains` configuration. Version 4.0.3 fixes the issue.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	terriajs-server	4.0.3	GHSA-w789-49fc-v8hr

Affected products (as reported)

Vendor	Product	Versions
TerriaJS	terriajs-server	< 4.0.3

Weakness: CWE-20, CWE-918 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

References

https://github.com/TerriaJS/terriajs-server/security/advisories/GHSA-w789-49fc-v8hr x_refsource_CONFIRM
https://github.com/TerriaJS/terriajs-server/commit/3aaa5d9717162b245ae4569232bbe7d8673c913f x_refsource_MISC