What is CVE-2026-18257?

CVE-2026-18257 is a medium-severity vulnerability in Systerel S2opc, classified under Improper Certificate Validation. CVSS score: 5.6/10. Published 2026-07-29.

How severe is CVE-2026-18257?

Medium severity. CVSS v3 base score is 5.6 out of 10.

Vulnerability in Systerel S2opc

CVE-2026-18257

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

Vulnerability class: Improper Certificate Validation

CVSS v3 metric

CVSS v3 base score 5.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.

Affected products

Systerel S2opc — versions 1.5.0

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

cve@gitlab.com

Frequently asked questions

What is CVE-2026-18257?: CVE-2026-18257 is a medium-severity vulnerability in Systerel S2opc, classified under Improper Certificate Validation. CVSS score: 5.6/10. Published 2026-07-29.
How severe is CVE-2026-18257?: Medium severity. CVSS v3 base score is 5.6 out of 10.