CVE-2026-6899: CWE-299: Improper Check for Certificate Revocation in Systerel S2OPC
CVE-2026-6899 is a medium severity vulnerability in Systerel's S2OPC library version 1. 5. 0. The issue involves improper checking for certificate revocation in the CycloneCrypto cryptographic wrapper, where only the first matching Certificate Revocation List (CRL) is considered, ignoring other valid CRLs from the same Certificate Authority (CA). This flaw may allow an OPC UA client and server to establish a connection using a revoked certificate.
AI Analysis
Technical Summary
The vulnerability CVE-2026-6899 in Systerel S2OPC 1.5.0 arises from an improper check for certificate revocation (CWE-299). Specifically, the CycloneCrypto wrapper only evaluates the first matching CRL and disregards other valid CRLs issued by the same CA. This incomplete revocation checking can result in acceptance of revoked certificates during OPC UA client-server connections, potentially undermining the trust model of the communication.
Potential Impact
An attacker could exploit this vulnerability to use a revoked certificate to establish a connection between an OPC UA client and server, potentially leading to unauthorized access or man-in-the-middle scenarios. The confidentiality, integrity, and availability of communications may be partially compromised. The CVSS 3.1 base score is 5.6 (medium), reflecting network attack vector, high attack complexity, no privileges required, no user interaction, and impacts on confidentiality, integrity, and availability.
Mitigation Recommendations
No official patch or remediation is currently available for this vulnerability. Users should monitor the vendor's advisories for updates. Until a fix is released, consider additional external controls to validate certificate revocation or restrict trust to certificates verified by out-of-band methods.
CVE-2026-6899: CWE-299: Improper Check for Certificate Revocation in Systerel S2OPC
Description
CVE-2026-6899 is a medium severity vulnerability in Systerel's S2OPC library version 1. 5. 0. The issue involves improper checking for certificate revocation in the CycloneCrypto cryptographic wrapper, where only the first matching Certificate Revocation List (CRL) is considered, ignoring other valid CRLs from the same Certificate Authority (CA). This flaw may allow an OPC UA client and server to establish a connection using a revoked certificate.
CVSS v3.1
Score 5.6medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-6899 in Systerel S2OPC 1.5.0 arises from an improper check for certificate revocation (CWE-299). Specifically, the CycloneCrypto wrapper only evaluates the first matching CRL and disregards other valid CRLs issued by the same CA. This incomplete revocation checking can result in acceptance of revoked certificates during OPC UA client-server connections, potentially undermining the trust model of the communication.
Potential Impact
An attacker could exploit this vulnerability to use a revoked certificate to establish a connection between an OPC UA client and server, potentially leading to unauthorized access or man-in-the-middle scenarios. The confidentiality, integrity, and availability of communications may be partially compromised. The CVSS 3.1 base score is 5.6 (medium), reflecting network attack vector, high attack complexity, no privileges required, no user interaction, and impacts on confidentiality, integrity, and availability.
Mitigation Recommendations
No official patch or remediation is currently available for this vulnerability. Users should monitor the vendor's advisories for updates. Until a fix is released, consider additional external controls to validate certificate revocation or restrict trust to certificates verified by out-of-band methods.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitLab
- Date Reserved
- 2026-04-23T07:01:03.918Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a27e32a8dd33fbd8512607f
Added to database: 6/9/2026, 9:55:54 AM
Last enriched: 6/9/2026, 10:11:17 AM
Last updated: 6/9/2026, 1:12:48 PM
Views: 5
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