CVE-2026-113618: Improper Server Certificate Validation in ZSIRep Client Library
The ZSIRep client library (ZSIREP.CLIENT.DLL) is vulnerable to improper server certificate validation. It registers a process-wide .NET callback that accepts any certificate for HTTPS connections without verification. This allows a man-in-the-middle attacker to impersonate the ZSIRep server and intercept or modify authentication data and documents. The callback persists after the client is closed, weakening other HTTPS connections in the same application.
The issue was fixed in version 2.12.3.1. The library is used in KS-SOMED (fixed in 2026.03.0.01), KS-PPS (fixed in 2026.03.1.0), KS-MEDIS (fixed in 2026.03.0.0), KS-SOLAB (fixed in 2026.3.1.0), and KS-ASW (fixed in 2026.3.0.1).
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ZSIREP.CLIENT.DLLto a version that resolves this vulnerability.Fixed in 2.12.3.1 - Upgrade
Upgrade
KS-SOMEDto a version that resolves this vulnerability.Fixed in 2026.03.0.01 - Upgrade
Upgrade
KS-PPSto a version that resolves this vulnerability.Fixed in 2026.03.1.0 - Upgrade
Upgrade
KS-MEDISto a version that resolves this vulnerability.Fixed in 2026.03.0.0 - Upgrade
Upgrade
KS-SOLABto a version that resolves this vulnerability.Fixed in 2026.3.1.0 - Upgrade
Upgrade
KS-ASWto a version that resolves this vulnerability.Fixed in 2026.3.0.1