CVE-2026-20012
A vulnerability in the Internet Key Exchange version 2 (IKEv2) feature of Cisco IOS Software, Cisco IOS XE Software, Cisco Secure Firewall Adaptive Security Appliance…
Published Mar 25, 2026 · corrected/updated Sep 17, 2026 · cisco secure firewall threat defense · evidence confidence high
A vulnerability in the Internet Key Exchange version 2 (IKEv2) feature of Cisco IOS Software, Cisco IOS XE Software, Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a memory leak, resulting in a denial of service (DoS) condition on an affected device. This vulnerability is due to improper parsing of IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. A successful exploit of Cisco IOS Software and IOS XE Software could allow the attacker to cause the affected device to reload, resulting in a DoS condition. A successful exploit of Cisco Secure Firewall ASA Software and Secure FTD Software could allow the attacker to partially exhaust system memory, resulting in system instability, such as the inability to establish new IKEv2 VPN sessions. A manual reboot of the device is required to recover from this condition.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-20012 is a high public vulnerability record for cisco secure firewall threat defense. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether cisco secure firewall threat defense is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: cisco/secure firewall threat defense (6.2.3); cisco/secure firewall threat defense (6.2.3.1); cisco/secure firewall threat defense (6.2.3.2); cisco/secure firewall threat defense (6.2.3.3). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 8.6, EPSS 0.4%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-401. Sources contributing to this record: cve_org, epss, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Mar 25, 2026 · NIST NVD
Detected
A vulnerability in the Internet Key Exchange version 2 (IKEv2) feature of Cisco IOS Software, Cisco IOS XE Software, Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a memory leak, resulting in a denial of service (DoS) condition on an affected device. This vulnerabil
Sep 17, 2026 · NIST NVD
Updated
A vulnerability in the Internet Key Exchange version 2 (IKEv2) feature of Cisco IOS Software, Cisco IOS XE Software, Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a memory leak, resulting in a denial of service (DoS) condition on an affected device. This vulnerabil
Affected
- cpe cisco/secure firewall threat defense6.2.3
- cpe cisco/secure firewall threat defense6.2.3.1
- cpe cisco/secure firewall threat defense6.2.3.2
- cpe cisco/secure firewall threat defense6.2.3.3
- cpe cisco/secure firewall threat defense6.2.3.4
- cpe cisco/secure firewall threat defense6.2.3.5
- cpe cisco/secure firewall threat defense6.2.3.6
- cpe cisco/secure firewall threat defense6.2.3.7
Sources
- CVE.orgVulnerability recordCVE-2026-20012
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-20012
30-day exploitation probability 0.4%
first.org - NIST NVDVulnerability recordCVE-2026-20012
A vulnerability in the Internet Key Exchange version 2 (IKEv2) feature of Cisco IOS Software, Cisco IOS XE Software, Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote at
nvd.nist.gov