CVE-2026-18257

MEDIUMPre-NVD 5.65.6—
EchelonGraph scoreMEDIUM confidence

Score 5.6 from GitHub Security Advisory published 2026-07-29. a secondary CVSS source baseline 5.6; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
5.6EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.6Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Improper validity period check for root issuer certificate in CycloneCrypto cryptographic wrapper of S2OPC allows a certificate issued by this root issuer to be considered trusted

CVSS v3
5.6
EG Score
5.6(medium)
EG Risk
25(Track)
EG Risk 25/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity56% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
1%
KEV
Not listed

Published

July 29, 2026

Last Modified

July 30, 2026

Advisory Details (1)

Auto-updated Jul 29, 2026
No patch confirmed yet.
generic

Systerel / S2OPC · GitLab

https://gitlab.com/systerel/S2OPC/-/work_items/1804

Vendor Advisories for CVE-2026-18257(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 69× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 23:17 UTCEG score recompute
  3. 2026-08-29 23:17 UTCGHSA enrichment
  4. 2026-08-28 21:41 UTCEPSS rescore
  5. 2026-08-27 14:25 UTCEPSS rescore
  6. 2026-08-27 12:13 UTCEG score recompute
  7. 2026-08-27 12:13 UTCGHSA enrichment
  8. 2026-08-26 14:46 UTCEPSS rescore
  9. 2026-08-26 10:29 UTCGHSA enrichment
  10. 2026-08-25 08:31 UTCEG score recompute
  11. 2026-08-25 08:30 UTCGHSA enrichment
  12. 2026-08-24 06:26 UTCGHSA enrichment
  13. 2026-08-23 04:43 UTCEG score recompute
  14. 2026-08-23 04:42 UTCGHSA enrichment
  15. 2026-08-23 00:19 UTCEPSS rescore
  16. 2026-08-22 02:59 UTCEG score recompute
  17. 2026-08-22 02:59 UTCGHSA enrichment
  18. 2026-08-21 23:49 UTCEPSS rescore
  19. 2026-08-21 01:12 UTCEG score recompute
  20. 2026-08-21 01:12 UTCGHSA enrichment
  21. 2026-08-20 22:55 UTCEPSS rescore
  22. 2026-08-19 23:29 UTCEG score recompute
  23. 2026-08-19 23:29 UTCGHSA enrichment
  24. 2026-08-19 17:03 UTCEPSS rescore
  25. 2026-08-18 21:45 UTCGHSA enrichment
Show 53 more
  1. 2026-08-17 20:01 UTCEG score recompute
  2. 2026-08-17 20:00 UTCGHSA enrichment
  3. 2026-08-17 13:47 UTCEPSS rescore
  4. 2026-08-16 18:16 UTCEG score recompute
  5. 2026-08-16 18:16 UTCGHSA enrichment
  6. 2026-08-16 14:56 UTCEPSS rescore
  7. 2026-08-15 16:33 UTCEG score recompute
  8. 2026-08-15 16:33 UTCGHSA enrichment
  9. 2026-08-15 01:30 UTCEPSS rescore
  10. 2026-08-14 14:49 UTCEG score recompute
  11. 2026-08-14 14:49 UTCGHSA enrichment
  12. 2026-08-13 22:00 UTCEPSS rescore
  13. 2026-08-13 13:06 UTCEG score recompute
  14. 2026-08-13 13:06 UTCGHSA enrichment
  15. 2026-08-12 13:50 UTCEPSS rescore
  16. 2026-08-12 11:23 UTCGHSA enrichment
  17. 2026-08-11 09:39 UTCEG score recompute
  18. 2026-08-11 09:39 UTCGHSA enrichment
  19. 2026-08-11 00:00 UTCEPSS rescore
  20. 2026-08-10 07:55 UTCGHSA enrichment
  21. 2026-08-09 06:12 UTCEG score recompute
  22. 2026-08-09 06:12 UTCGHSA enrichment
  23. 2026-08-08 16:37 UTCEPSS rescore
  24. 2026-08-08 04:29 UTCEG score recompute
  25. 2026-08-08 04:29 UTCGHSA enrichment
  26. 2026-08-07 02:46 UTCEG score recompute
  27. 2026-08-07 02:46 UTCGHSA enrichment
  28. 2026-08-06 13:46 UTCEPSS rescore
  29. 2026-08-06 01:03 UTCEG score recompute
  30. 2026-08-06 01:03 UTCGHSA enrichment
  31. 2026-08-05 19:17 UTCEPSS rescore
  32. 2026-08-04 23:20 UTCEG score recompute
  33. 2026-08-04 23:20 UTCGHSA enrichment
  34. 2026-08-04 15:10 UTCEPSS rescore
  35. 2026-08-04 10:38 UTCEPSS rescore
  36. 2026-08-03 21:37 UTCGHSA enrichment
  37. 2026-08-02 19:54 UTCEG score recompute
  38. 2026-08-02 19:54 UTCGHSA enrichment
  39. 2026-08-02 02:26 UTCEPSS rescore
  40. 2026-08-01 18:10 UTCEG score recompute
  41. 2026-08-01 18:10 UTCGHSA enrichment
  42. 2026-08-01 04:15 UTCEPSS rescore
  43. 2026-07-31 16:27 UTCEG score recompute
  44. 2026-07-31 16:27 UTCGHSA enrichment
  45. 2026-07-30 14:38 UTCEG score recompute
  46. 2026-07-30 14:38 UTCGHSA enrichment
  47. 2026-07-29 19:32 UTCEG score recompute
  48. 2026-07-29 19:32 UTCGHSA enrichment
  49. 2026-07-29 18:34 UTCEG score recompute
  50. 2026-07-29 18:34 UTCGHSA enrichment
  51. 2026-07-29 17:26 UTCEG score recompute
  52. 2026-07-29 16:38 UTCEG score recompute
  53. 2026-07-29 16:37 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-18257?
CVE-2026-18257 is a medium vulnerability published on July 29, 2026. Improper validity period check for root issuer certificate in CycloneCrypto cryptographic wrapper of S2OPC allows a certificate issued by this root issuer to be considered trusted
When was CVE-2026-18257 disclosed?
CVE-2026-18257 was first published in the National Vulnerability Database on July 29, 2026, with the most recent update on July 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18257 actively exploited?
CVE-2026-18257 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 99.1% of all scored CVEs.
What is the CVSS score of CVE-2026-18257?
CVE-2026-18257 has a CVSS v3 base score of 5.6 (NVD).
How do I remediate CVE-2026-18257?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18257, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-18257

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