CVE-2026-20331

CRITICALPre-NVD 9.69.6—
EchelonGraph scoreHIGH confidence

Score 9.6 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-16. a secondary CVSS source baseline 9.6; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
9.6EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.6Exploit: None knownExposed: 0

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

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense Software and Cisco Secure Firewall Management Center Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities.   The vulnerabilities tracked by CVE-2026-20331 are related to the failure of protection mechanisms issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-693.

CVSS v3
9.6
EG Score
9.6(high)
EG Risk
43(Track)
EG Risk 43/100SSVC: 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
Severity96% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
14%
KEV
Not listed

Published

September 16, 2026

Last Modified

September 18, 2026

Advisory Details (1)

Auto-updated Sep 17, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic🔴 Active Exploitation

Cisco Secure Firewall Adaptive Security Appliance, Secure Firewall Threat Defense, and Secure Firewall Management Center Software Hardening Release: September 2026

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-asaftdfmc-uvpPROhN

Vendor Advisories for CVE-2026-20331(2)

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 34× in last 7d / 34× 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. 2026-09-19 11:05 UTCGHSA enrichment
  2. 2026-09-19 07:27 UTCGHSA enrichment
  3. 2026-09-19 03:50 UTCGHSA enrichment
  4. 2026-09-19 00:12 UTCGHSA enrichment
  5. 2026-09-18 20:35 UTCEG score recompute
  6. 2026-09-18 20:35 UTCGHSA enrichment
  7. 2026-09-18 19:27 UTCEPSS rescore
  8. 2026-09-18 19:20 UTCEG score recompute
  9. 2026-09-18 19:20 UTCGHSA enrichment
  10. 2026-09-18 16:42 UTCGHSA enrichment
  11. 2026-09-18 13:04 UTCGHSA enrichment
  12. 2026-09-18 09:26 UTCGHSA enrichment
  13. 2026-09-18 05:49 UTCGHSA enrichment
  14. 2026-09-18 02:12 UTCGHSA enrichment
  15. 2026-09-17 22:34 UTCEG score recompute
  16. 2026-09-17 22:34 UTCGHSA enrichment
  17. 2026-09-17 18:55 UTCGHSA enrichment
  18. 2026-09-17 15:14 UTCGHSA enrichment
  19. 2026-09-17 11:35 UTCGHSA enrichment
  20. 2026-09-17 07:57 UTCGHSA enrichment
  21. 2026-09-17 04:19 UTCEG score recompute
  22. 2026-09-17 04:19 UTCGHSA enrichment
  23. 2026-09-17 04:05 UTCGHSA enrichment
  24. 2026-09-17 03:25 UTCGHSA enrichment
  25. 2026-09-16 23:47 UTCGHSA enrichment
Show 9 more
  1. 2026-09-16 20:09 UTCEG score recompute
  2. 2026-09-16 20:09 UTCGHSA enrichment
  3. 2026-09-16 19:25 UTCEG score recompute
  4. 2026-09-16 19:25 UTCGHSA enrichment
  5. 2026-09-16 18:24 UTCEG score recompute
  6. 2026-09-16 17:45 UTCEG score recompute
  7. 2026-09-16 17:26 UTCEG score recompute
  8. 2026-09-16 17:05 UTCEG score recompute
  9. 2026-09-16 17:04 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-20331?
CVE-2026-20331 is a critical vulnerability published on September 16, 2026. As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense Software and Cisco Secure Firewall Management Center Software engineering team has conducted a comprehensive internal security…
When was CVE-2026-20331 disclosed?
CVE-2026-20331 was first published in the National Vulnerability Database on September 16, 2026, with the most recent update on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-20331 actively exploited?
CVE-2026-20331 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 86.0% of all scored CVEs.
What is the CVSS score of CVE-2026-20331?
CVE-2026-20331 has a CVSS v3 base score of 9.6 (NVD).
How do I remediate CVE-2026-20331?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-20331, 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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