In Eclipse Theia versions up to and including 0.16.0, in the notification messages there is no HTML escaping, so Javascript code can run.
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NEclipse Theia
APPEclipse≤ 0.16.0
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CHECK WITH VENDOR
No clear patch data available. Check vendor references.
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