Vulnerability in KGS Software tia Viewer software

CERT Polska has received a report about vulnerability in KGS Software tia Viewer software and participated in coordination of its disclosure.

The vulnerabilityCVE-2026-105987: KGS Software tia Viewer is vulnerable to Stored XSS via the annotation API. Due to the lack of input validation, an authenticated attacker can inject arbitrary JavaScript payload into a stickynote annotation. When any user opens the document, the viewer renders the annotation and the browser executes the payload. This may lead to compromising the user's session.

This issue has been fixed in version 1.2.8.

We thank Dawid Dudek (4c1d8urn) for the responsible vulnerability report.