CyberSecBulletin
CVE-2026-20222NVD status: Awaiting Analysis

Cisco Secure Firewall Adaptive Security…: Missing Release of Memory after Effective Lifetime

Published Updated By the CyberSecBulletin desk

CVE-2026-20222 is a high-severity missing release of memory after effective lifetime vulnerability in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software from Cisco, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected Cisco Secure Firewall Adaptive Security Appliance (ASA) Software versions: 9.19.1; 9.19.1.5; 9.19.1.9, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.25% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco Secure Firewall Adaptive Security Appliance (ASA) Software9.19.1; 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; and 32 more rangesNot stated
CiscoCisco Secure Firewall Threat Defense (FTD) Software7.3.0; 7.3.1; 7.3.1.1; 7.4.0; 7.4.1; 7.4.1.1; 7.3.1.2; 7.6.0; and 17 more rangesNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
AdjacentThe attacker must be on the same local network segment.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H. Scored by CNA (cisco.com).

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Missing Release of Memory after Effective Lifetime

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

How developers prevent this class of flaw

  • Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone. For example, glibc in Linux provides protection against free of invalid pointers. When using Xcode to target OS X or iOS, enable automatic reference counting (ARC). To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Consider using the Boehm-Demers-Weiser garbage collector (bdwgc), which can help avoid leaks.

More Missing Release of Memory after Effective Lifetime vulnerabilities (CWE-401)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software

All Cisco Secure Firewall Adaptive Security Appliance (ASA) Software vulnerabilities

Recent Missing Release of Memory after Effective Lifetime vulnerabilities

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