CVE-2026-6899

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.

Is your site exposed to CVE-2026-6899?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.6

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

EPSS — Exploit Prediction

0.0011

Probability of exploitation

0.01%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-299 CWE-299

References

Other References

https://gitlab.com/systerel/S2OPC/-/work_items/1739

Frequently Asked Questions

What is CVE-2026-6899? +

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. It has a CVSS v3.1 base score of 5.6 (MEDIUM).

How severe is CVE-2026-6899? +

CVE-2026-6899 has a CVSS v3.1 score of 5.6 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0011, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-6899? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-11955

Incorrect validation of OCSP certificates vulnerability in TheGreenBow VPN, versions 7.5 and 7.6. During the IKEv2 authentication step, the OCSP-enabled …

CVE-2025-3085 8.1

A MongoDB server under specific conditions running on Linux with TLS and CRL revocation status checking enabled, fails to check …

CVE-2025-36057 5.2

IBM Cognos Analytics Mobile (iOS) 1.1.0 through 1.1.22 is vulnerable to authentication bypass by using the Local Authentication Framework library …

CVE-2024-56138 4.0

notion-go is a collection of libraries for supporting sign and verify OCI artifacts. Based on Notary Project specifications. This issue …