CVE-2026-20250 (CVSS 8.6)

Description

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.

Is your site exposed to CVE-2026-20250?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

8.6

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0055

Probability of exploitation

0.45%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-772 CWE-772

References

Other References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-dtls-dos-Kp57HkyO

Frequently Asked Questions

What is CVE-2026-20250? +

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. It has a CVSS v3.1 base score of 8.6 (HIGH).

How severe is CVE-2026-20250? +

CVE-2026-20250 has a CVSS v3.1 score of 8.6 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0055, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-20250? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-95108

One logical thread of a user-mode ThreadX module costs the Module Manager's shared object pool two allocations, not one. The …

CVE-2026-115793

P-Net before 1.0.3 does not release the RPC session allocated for an RPC request that names an unknown interface or …

CVE-2026-118262

Echo is a Go web framework. From 4.15.0 until 4.16.1 and 5.4.1, Echo's Proxy middleware can retain a handler, copy …

CVE-2026-45287

OpenTelemetry-Go is the Go implementation of OpenTelemetry. Prior to version 0.0.17, `go.opentelemetry.io/otel/schema/v1.0` and `go.opentelemetry.io/otel/schema/v1.1` leaks one file descriptor on each …

CVE-2026-35227

An unauthenticated remote attacker may exhaust all available TCP connections in the CODESYS Modbus TCP Server stack if a race …

CVE-2026-69664

Missing Release of Resource after Effective Lifetime vulnerability in Erlang/OTP inets httpd allows an unauthenticated remote attacker to cause denial …