CVE-2026-18257: Systerel s2opc

Medium severity, CVSS 5.6. EPSS: 0.2% chance of exploitation in the next 30 days.

Improper validity period check for root issuer certificate in CycloneCrypto cryptographic wrapper of S2OPC allows a certificate issued by this root issuer to be considered trusted

Affected products

• Systerel s2opc: from 1.5.0, before 2.0.0 (fixed in 2.0.0)

Published 2026-07-29. Last modified 2026-07-30.