CVE-2026-6899 Improper Check for Certificate Revocation in S2OPC
Attackers can bypass certificate revocation checks in S2OPC by exploiting CRL handling flaws, allowing connections with revoked certificates.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-6899?
CVE-2026-6899 is a medium-severity vulnerability in Systerel S2OPC, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-299
Which versions are affected by CVE-2026-6899?
How do I fix CVE-2026-6899?
No fix has been published for CVE-2026-6899 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-6899 being exploited?
There is no known exploitation of CVE-2026-6899 in the wild and no public exploit code.
Sources
Also known as GHSA-j893-vcpr-rgfc.