Cross-site scripting in TerriaJS-Server - CVE-2026-77636
Published: September 15, 2026
Vulnerability identifier: #VU149916
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-77636
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary script in a victim's browser.
The vulnerability exists due to improper content-type handling in the gist-backed share resolver when a browser directly navigates to a raw share endpoint. A remote attacker can host crafted markup in a public gist and distribute its share URL to execute arbitrary script in a victim's browser.
User interaction is required to open the crafted URL, and only deployments configured with a gist-backed share URL prefix are affected.
Affected software
TerriaJS-Server
How to mitigate CVE-2026-77636
Install security update from vendor's website.
TerriaJS-Server - update to 5.0.0