VDB-369484 · CVE-2026-6899 · GCVE-0-2026-6899

Systerel S2OPC up to 1.7.2 improper check for certificate revocation

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.5	$0-$5k	0.00

Summaryinfo

A vulnerability labeled as problematic has been found in Systerel S2OPC up to 1.7.2. Impacted is an unknown function. Executing a manipulation can lead to improper check for certificate revocation. The identification of this vulnerability is CVE-2026-6899. The attack may be launched remotely. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Systerel S2OPC up to 1.7.2. It has been declared as problematic. This vulnerability affects an unknown part. The manipulation with an unknown input leads to a improper check for certificate revocation vulnerability. The CWE definition for the vulnerability is CWE-299. The product does not check or incorrectly checks the revocation status of a certificate, which may cause it to use a certificate that has been compromised. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The weakness was shared by Systerel. The advisory is shared for download at gitlab.com. This vulnerability was named CVE-2026-6899 since 04/23/2026. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1557.003.

Upgrading to version 1.7.3 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

Systerel

Name

S2OPC

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.6
VulDB Temp Score: 5.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.6
CNA Vector (GitLab): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper check for certificate revocation
CWE: CWE-299 / CWE-298 / CWE-295
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: S2OPC 1.7.3

Timelineinfo

04/23/2026 CVE reserved
06/09/2026 +47 days Advisory disclosed
06/09/2026 +0 days VulDB entry created
06/09/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: gitlab.com
Researcher: Systerel
Status: Confirmed

CVE: CVE-2026-6899 (🔒)
GCVE (CVE): GCVE-0-2026-6899
GCVE (VulDB): GCVE-100-369484

Entryinfo

Created: 06/09/2026 12:33
Changes: 06/09/2026 12:33 (63)
Complete: 🔍
Cache ID: 216::103