CVE-2026-20307

CRITICALPre-NVD 9.99.9—
EchelonGraph scoreHIGH confidence

Score 9.9 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-16. a secondary CVSS source baseline 9.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
9.9EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.9Exploit: None knownExposed: 0

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

A vulnerability in the web-based management interface of Cisco ISE could allow an authenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device. To exploit this vulnerability, the attacker must have at least low-privileged administrative credentials. This vulnerability is due to insecure deserialization of a user-supplied Java byte stream. An attacker could exploit this vulnerability by sending a crafted serialized Java object to the web-based management interface of an affected device. A successful exploit could allow the attacker to execute arbitrary code on the device and elevate privileges to root. In single-node deployments, successful exploitation of this vulnerability could cause the affected ISE node to become unavailable, resulting in a denial of service (DoS) condition. In that condition, endpoints that have not already authenticated would be unable to access the network until the node is restored.

CVSS v3
9.9
EG Score
9.9(high)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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
Severity99% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
60%
KEV
Not listed

Published

September 16, 2026

Last Modified

September 17, 2026

Advisory Details (1)

Auto-updated Sep 17, 2026
No patch confirmed yet.
generic

Cisco Identity Services Engine Remote Code Execution Vulnerabilities

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-rce-se7bYU57

Vendor Advisories for CVE-2026-20307(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 31× in last 7d / 31× 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 10:58 UTCGHSA enrichment
  2. 2026-09-19 06:54 UTCGHSA enrichment
  3. 2026-09-19 02:51 UTCGHSA enrichment
  4. 2026-09-18 22:47 UTCEG score recompute
  5. 2026-09-18 22:47 UTCGHSA enrichment
  6. 2026-09-18 19:27 UTCEPSS rescore
  7. 2026-09-18 18:43 UTCGHSA enrichment
  8. 2026-09-18 14:39 UTCGHSA enrichment
  9. 2026-09-18 10:35 UTCGHSA enrichment
  10. 2026-09-18 06:30 UTCGHSA enrichment
  11. 2026-09-18 02:26 UTCGHSA enrichment
  12. 2026-09-17 22:22 UTCEG score recompute
  13. 2026-09-17 22:22 UTCGHSA enrichment
  14. 2026-09-17 18:18 UTCGHSA enrichment
  15. 2026-09-17 12:19 UTCEG score recompute
  16. 2026-09-17 12:19 UTCGHSA enrichment
  17. 2026-09-17 11:49 UTCEG score recompute
  18. 2026-09-17 11:49 UTCGHSA enrichment
  19. 2026-09-17 08:23 UTCGHSA enrichment
  20. 2026-09-17 04:19 UTCEG score recompute
  21. 2026-09-17 04:19 UTCGHSA enrichment
  22. 2026-09-17 04:05 UTCEG score recompute
  23. 2026-09-17 04:05 UTCGHSA enrichment
  24. 2026-09-17 00:13 UTCGHSA enrichment
  25. 2026-09-16 20:09 UTCEG score recompute
Show 6 more
  1. 2026-09-16 20:09 UTCGHSA enrichment
  2. 2026-09-16 19:25 UTCEG score recompute
  3. 2026-09-16 19:25 UTCGHSA enrichment
  4. 2026-09-16 17:26 UTCEG score recompute
  5. 2026-09-16 17:05 UTCEG score recompute
  6. 2026-09-16 17:04 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-20307?
CVE-2026-20307 is a critical vulnerability published on September 16, 2026. A vulnerability in the web-based management interface of Cisco ISE could allow an authenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device. To exploit this vulnerability, the attacker must have at least low-privileged administrative…
When was CVE-2026-20307 disclosed?
CVE-2026-20307 was first published in the National Vulnerability Database on September 16, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-20307 actively exploited?
CVE-2026-20307 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 40.2% of all scored CVEs.
What is the CVSS score of CVE-2026-20307?
CVE-2026-20307 has a CVSS v3 base score of 9.9 (NVD).
How do I remediate CVE-2026-20307?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-20307, 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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