A vulnerability in Datagram TLS (DTLS) message handling of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software for Cisco Secure Firewall 3100 Series and 4200 Series devices could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper resource management when processing certain DTLS messages. An attacker could exploit this vulnerability by sending a crafted stream of DTLS traffic to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
CVE-2026-20250
Score 8.6 from GitHub Security Advisory (severity: HIGH) published 2026-09-16. the CNA's CVSS baseline 8.6; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.6
- EG Score
- 8.6(high)
- EG Risk
- 54(Track)EG Risk 54/100SSVC: 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 computedSeverity86% × 45%Exploitation1% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 1%
- EPSS %ILE
- 45%
- KEV
- Not listed
Published
September 16, 2026
Last Modified
September 18, 2026
Advisory Details (1)
Auto-updated Sep 16, 2026Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software for Secure Firewall 3100 and 4200 Series DTLS Denial of Service Vulnerability
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-dtls-dos-Kp57HkyOVendor Advisories for CVE-2026-20250(2)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- GHSA-rf4g-28mq-c9qrGitHub Security AdvisoriesHigh
A vulnerability in Datagram TLS (DTLS) message handling of Cisco Secure Firewall Adaptive...
- cisco-sa-asaftd-dtls-dos-Kp57HkyOCisco PSIRT openVulnHigh
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software for Secure Firewall 3100 and 4200 Series DTLS Denial of Service Vulnerability
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 17× in last 7d / 17× 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.
- 2026-09-19 08:00 UTCEG score recompute
- 2026-09-19 08:00 UTCGHSA enrichment
- 2026-09-18 19:27 UTCEPSS rescore
- 2026-09-18 19:20 UTCEG score recompute
- 2026-09-18 19:20 UTCGHSA enrichment
- 2026-09-18 13:42 UTCGHSA enrichment
- 2026-09-18 04:05 UTCEG score recompute
- 2026-09-18 04:05 UTCGHSA enrichment
- 2026-09-17 15:24 UTCEG score recompute
- 2026-09-17 15:24 UTCGHSA enrichment
- 2026-09-17 14:59 UTCEG score recompute
- 2026-09-17 14:59 UTCGHSA enrichment
- 2026-09-17 10:08 UTCEG score recompute
- 2026-09-17 10:08 UTCGHSA enrichment
- 2026-09-16 21:27 UTCEG score recompute
- 2026-09-16 20:43 UTCEG score recompute
- 2026-09-16 20:29 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-20250?
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What is the CVSS score of CVE-2026-20250?
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Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-20250
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