Vulnerability · Published Jun 9, 2026 · Assigned by GitLab
CVE-2026-6899Improper Check for Certificate Revocation in S2OPC
Medium 5.6
In plain English
A medium-severity security flaw in S2OPC from Systerel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 1% of all known vulnerabilities).
Severity (CVSS 3.1)5.6Medium
Exploit odds (30 days)0.1%top 98.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Check for certificate revocation only considers the first matching CRL and ignores other valid CRLs of the same CA in the CycloneCrypto cryptographic wrapper of S2OPC library. It might allow connection between an OPC UA client and server using a revoked certificate.
Affected products (as reported)
Weakness: CWE-299 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L