CVE-2026-6899: Systerel S2OPC · Improper Check for Certificate Revocation
Affects Systerel S2OPCSource CVE Database V5
Not known to be exploited · CVSS 5.6 Medium : upgrade to 1.7.3 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.7.3
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:LExploitation evidence
Disclosed: evidence found.
CVE published 9 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade Systerel S2OPC to 1.7.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| SysterelS2OPC | Affected
| Fixed in
|
GitHubsysterel/S2OPCpkg:github/systerel/S2OPCOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, consider additional external controls to validate certificate revocation or restrict trust to certificates verified by out-of-band methods.
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.