CVE-2026-20066

MEDIUMPre-NVD 5.85.8—
EchelonGraph scoreMEDIUM confidence

Score 5.8 from GitHub Security Advisory published 2026-03-04. a secondary CVSS source baseline 5.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
5.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.8Exploit: None knownExposed: 0

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

Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in the JSTokenizer normalization logic when the HTTP inspection normalizes JavaScript. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection that is parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine restarts unexpectedly. JSTokenizer is not enabled by default.

CVSS v3
5.8
EG Score
5.8(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: 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
Severity58% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
39%
KEV
Not listed

Published

March 4, 2026

Last Modified

August 19, 2026

Advisory Details (1)

Auto-updated Aug 4, 2026
No patch confirmed yet.
generic

Multiple Cisco Products Snort 3 Denial of Service Vulnerabilities

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-multi-dos-XFWkWSwz

Vendor Advisories for CVE-2026-20066(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 4× in last 7d / 25× 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. 2026-09-18 19:27 UTCEPSS rescore
  2. 2026-09-16 14:07 UTCEPSS rescore
  3. 2026-09-16 05:14 UTCEPSS rescore
  4. 2026-09-13 16:46 UTCEPSS rescore
  5. 2026-09-12 15:00 UTCEPSS rescore
  6. 2026-09-11 14:52 UTCEPSS rescore
  7. 2026-09-11 09:36 UTCEPSS rescore
  8. 2026-09-10 09:34 UTCEPSS rescore
  9. 2026-09-08 22:00 UTCEPSS rescore
  10. 2026-09-07 16:01 UTCEPSS rescore
  11. 2026-09-06 13:47 UTCEPSS rescore
  12. 2026-09-06 10:00 UTCOSV refresh
  13. 2026-09-04 05:06 UTCEPSS rescore
  14. 2026-09-02 14:11 UTCEPSS rescore
  15. 2026-09-01 13:53 UTCEPSS rescore
  16. 2026-09-01 04:39 UTCEPSS rescore
  17. 2026-08-30 19:17 UTCEPSS rescore
  18. 2026-08-30 01:22 UTCEPSS rescore
  19. 2026-08-28 21:41 UTCEPSS rescore
  20. 2026-08-27 14:25 UTCEPSS rescore
  21. 2026-08-26 14:46 UTCEPSS rescore
  22. 2026-08-25 13:48 UTCEPSS rescore
  23. 2026-08-23 00:19 UTCEPSS rescore
  24. 2026-08-21 23:49 UTCEPSS rescore
  25. 2026-08-20 22:55 UTCEPSS rescore
Show 43 more
  1. 2026-08-19 20:36 UTCEG score recompute
  2. 2026-08-19 20:36 UTCGHSA enrichment
  3. 2026-08-19 17:03 UTCEPSS rescore
  4. 2026-08-18 13:48 UTCEPSS rescore
  5. 2026-08-17 13:47 UTCEPSS rescore
  6. 2026-08-16 14:56 UTCEPSS rescore
  7. 2026-08-16 02:14 UTCEPSS rescore
  8. 2026-08-15 01:30 UTCEPSS rescore
  9. 2026-08-14 08:35 UTCEG score recompute
  10. 2026-08-14 08:35 UTCGHSA enrichment
  11. 2026-08-13 22:00 UTCEPSS rescore
  12. 2026-08-13 01:09 UTCEG score recompute
  13. 2026-08-13 01:09 UTCGHSA enrichment
  14. 2026-08-12 13:50 UTCEPSS rescore
  15. 2026-08-11 23:15 UTCEG score recompute
  16. 2026-08-11 23:15 UTCGHSA enrichment
  17. 2026-08-11 13:42 UTCEPSS rescore
  18. 2026-08-11 00:00 UTCEPSS rescore
  19. 2026-08-10 10:07 UTCEG score recompute
  20. 2026-08-10 10:07 UTCGHSA enrichment
  21. 2026-08-09 13:46 UTCEPSS rescore
  22. 2026-08-09 08:13 UTCEG score recompute
  23. 2026-08-09 08:13 UTCGHSA enrichment
  24. 2026-08-08 16:37 UTCEPSS rescore
  25. 2026-08-07 20:05 UTCEG score recompute
  26. 2026-08-07 20:05 UTCGHSA enrichment
  27. 2026-08-06 13:46 UTCEPSS rescore
  28. 2026-08-06 02:41 UTCEG score recompute
  29. 2026-08-06 02:41 UTCGHSA enrichment
  30. 2026-08-05 19:17 UTCEPSS rescore
  31. 2026-08-04 15:10 UTCEPSS rescore
  32. 2026-08-04 10:38 UTCEPSS rescore
  33. 2026-08-04 02:36 UTCEG score recompute
  34. 2026-08-04 02:36 UTCGHSA enrichment
  35. 2026-08-03 10:35 UTCEPSS rescore
  36. 2026-08-02 18:59 UTCEG score recompute
  37. 2026-08-02 18:59 UTCGHSA enrichment
  38. 2026-08-02 02:26 UTCEPSS rescore
  39. 2026-08-01 04:15 UTCEPSS rescore
  40. 2026-07-30 01:30 UTCEPSS rescore
  41. 2026-07-27 14:13 UTCEPSS rescore
  42. 2026-07-27 12:54 UTCEG score recompute
  43. 2026-07-27 12:54 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-20066?
CVE-2026-20066 is a medium vulnerability published on March 4, 2026. Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in the JSTokenizer…
When was CVE-2026-20066 disclosed?
CVE-2026-20066 was first published in the National Vulnerability Database on March 4, 2026, with the most recent update on August 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-20066 actively exploited?
CVE-2026-20066 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 61.2% of all scored CVEs.
What is the CVSS score of CVE-2026-20066?
CVE-2026-20066 has a CVSS v3 base score of 5.8 (NVD).
How do I remediate CVE-2026-20066?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-20066, 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

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