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CVE-2026-6899

Improper Check for Certificate Revocation in S2OPC

5.6 Medium

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.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
High
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
Low
Integrity
Low
Availability
Low

Exploit likelihood

0.11%Up 0.1 points since Jun 9, 2026
90%50%10%1%

What each source reports

CVE List Score used 5.6

Improper Check for Certificate Revocation in S2OPC

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.

Record
CVE-2026-6899
CVSS 3.1
5.6 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Weakness
CWE-299
Updated
2026-11-02
EUVDEUVD-2026-35380 5.6

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.

Record
EUVD-2026-35380
CVSS 3.1
5.6 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Updated
2026-11-02
GitHub AdvisoriesGHSA-j893-vcpr-rgfc 5.6

Check for certificate revocation only considers the first matching CRL and ignores other valid...

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.

Record
GHSA-j893-vcpr-rgfc
CVSS 3.1
5.6 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Weakness
CWE-299
Updated
2026-11-02
NVD 5.6

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.

Record
CVE-2026-6899
CVSS 3.1
5.6 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Weakness
CWE-299
Updated
2026-11-02

Affected products

History

History
RecordedChangedSources
first indexedCVE List, EUVD, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-6899 is a medium vulnerability (CVSS 5.6) in Systerel S2opc, published June 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.11%, the 1st percentile. No source names a fixed version.

References

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