PatchTheCVECVE-2026-20012: A vulnerability in the Internet Key Exchange version 2 (IKEv2) feature of Cisco IOS Software, Cisco IOS XE Sof
CVE-2026-20012 is a high-severity flaw (CVSS 8.6) affecting secure firewall threat defense, adaptive security appliance software, ios. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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
Why this priority
- High severity
- Remotely exploitable, no login, no user action
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 8.6 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.4% (top 70%) |
| CISA exploited list | No |
| Weakness | CWE-401 |
| Published | 2026-03-25 |
| Last modified | 2026-09-17 |
Last updated 2026-09-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-20012?
secure firewall threat defense: downgrade or apply the listed mitigation; adaptive security appliance software: mitigate or apply the listed mitigation; ios: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2026-20012 being exploited?
CVE-2026-20012 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-20012 affect?
CVE-2026-20012 affects secure firewall threat defense, adaptive security appliance software, ios. Severity is high (CVSS 8.6). 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 c
How urgent is CVE-2026-20012?
Priority 42/100. High severity; Remotely exploitable, no login, no user action
Software pages
iOS vulnerabilities · Cisco IOS XE vulnerabilities · Cisco ASA vulnerabilities · Cisco vulnerabilities
Related CVEs
- CVE-2026-20349 HIGH 8.6 EXPLOITED MITIGATE DOWNGRADE Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection Vulnerability
- CVE-2026-20005 MEDIUM 5.8 DOWNGRADE DOWNGRADE Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an un
- CVE-2026-20006 MEDIUM 5.8 DOWNGRADE A vulnerability in the TLS cryptography functionality of the Snort 3 Detection Engine of Cisco Secure Firewall
- CVE-2026-20007 MEDIUM 5.8 DOWNGRADE A vulnerability in the Snort 2 and Snort 3 deep packet inspection of Cisco Secure Firewall Threat Defense (FTD
- CVE-2026-20052 MEDIUM 5.8 DOWNGRADE A vulnerability in the memory management handling for the Snort 3 Detection Engine of Cisco Secure Firewall Th