Vulnerability · Published Oct 27, 2026 · Assigned by CERT-PL

CVE-2026-105987Stored XSS in KGS Software tia Viewer

Medium 5.1

In plain English

A medium-severity cross-site scripting in tia Viewer from KGS Software. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 15% of all known vulnerabilities).

Severity (CVSS 4.0)5.1Medium

Exploit odds (30 days)0.2%top 84.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
KGS Software	tia Viewer	0 – before 1.2.8

Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

References

https://cert.pl/en/posts/2026/10/CVE-2026-105987 third-party-advisory
https://www.kgs-software.com/en/products/tia-viewer product