CVE-2026-20343

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-16. a secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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

A vulnerability in a critical API for Cisco Secure FMC Software could allow an unauthenticated, remote attacker to download sensitive files and use unbounded disk space. This vulnerability exists because a critical API lacks authentication. An attacker could exploit this vulnerability by repeatedly invoking the API. A successful exploit could allow the attacker to download sensitive files that should be restricted and consume disk space so the device could become unresponsive, causing a DoS condition.

CVSS v3
7.5
EG Score
7.5(high)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
38%
KEV
Not listed

Published

September 16, 2026

Last Modified

September 18, 2026

Advisory Details (1)

Auto-updated Sep 16, 2026
No patch confirmed yet.
generic

Cisco Secure Firewall Management Center Software Vulnerabilities

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-mulivulns-4PsnFwvx

Vendor Advisories for CVE-2026-20343(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 16× in last 7d / 16× 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 03:16 UTCEG score recompute
  2. 2026-09-19 03:16 UTCGHSA enrichment
  3. 2026-09-18 19:27 UTCEPSS rescore
  4. 2026-09-18 15:26 UTCEG score recompute
  5. 2026-09-18 15:26 UTCGHSA enrichment
  6. 2026-09-18 14:54 UTCEG score recompute
  7. 2026-09-18 14:54 UTCGHSA enrichment
  8. 2026-09-18 13:41 UTCGHSA enrichment
  9. 2026-09-18 08:57 UTCGHSA enrichment
  10. 2026-09-17 21:07 UTCEG score recompute
  11. 2026-09-17 21:07 UTCGHSA enrichment
  12. 2026-09-17 09:17 UTCEG score recompute
  13. 2026-09-17 09:17 UTCGHSA enrichment
  14. 2026-09-16 21:27 UTCEG score recompute
  15. 2026-09-16 20:35 UTCEG score recompute
  16. 2026-09-16 20:29 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-20343?
CVE-2026-20343 is a high vulnerability published on September 16, 2026. A vulnerability in a critical API for Cisco Secure FMC Software could allow an unauthenticated, remote attacker to download sensitive files and use unbounded disk space. This vulnerability exists because a critical API lacks authentication. An attacker could exploit this vulnerability by…
When was CVE-2026-20343 disclosed?
CVE-2026-20343 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-2026-20343 actively exploited?
CVE-2026-20343 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 61.5% of all scored CVEs.
What is the CVSS score of CVE-2026-20343?
CVE-2026-20343 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-20343?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-20343, 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-2026-20343

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