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CVE-2026-20012

Cisco Secure Firewall Threat Defense vulnerability

8.6 HIGHEPSS 0.35%
  1. Published25 Mar 2026

Description

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.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeChanged
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Affected products

Cisco Secure Firewall Threat Defense6.2.3 · 6.2.3.1 · 6.2.3.10 · 6.2.3.11
Cisco Adaptive Security Appliance Software9.12.1 · 9.12.1.2 · 9.12.1.3 · 9.12.2

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

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Frequently asked

Is CVE-2026-20012 being actively exploited?

CVE-2026-20012 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.35%.

How severe is CVE-2026-20012?

CVE-2026-20012 has a CVSS 3.1 base score of 8.6, rated high. EPSS estimates a 0.35% probability of exploitation.

Which products are affected by CVE-2026-20012?

Affected products include Cisco Secure Firewall Threat Defense, Cisco Adaptive Security Appliance Software.

How do I fix CVE-2026-20012?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-20012 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.