Findings

Vulnerability · CVE-2026-20013

A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to cause a DoS…

Published Mar 4, 2026 · corrected/updated Aug 11, 2026 · cisco adaptive security appliance software · evidence confidence high

A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device that may also impact the availability of services to devices elsewhere in the network. This vulnerability is due to memory exhaustion caused by not freeing memory during IKEv2 packet processing. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. A successful exploit could allow the attacker to exhaust resources, causing a DoS condition that will eventually require the device to manually reload.

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-2026-20013 is a medium public vulnerability record for cisco adaptive security appliance software. 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 adaptive security appliance software is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: cisco/adaptive security appliance software; cisco/secure firewall threat defense. 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 5.8, EPSS 0.3%. 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.

  1. Mar 4, 2026 · NIST NVD

    Detected

    A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device that may also impact the availability of services to devices elsewhere in the network. This vulnerability is due to memory exhaustion caused by not freeing memory during IKEv2 packet processing. An at

  2. Aug 11, 2026 · NIST NVD

    Updated

    A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device that may also impact the availability of services to devices elsewhere in the network. This vulnerability is due to memory exhaustion caused by not freeing memory during IKEv2 packet processing. An at

Affected

  • cpe cisco/adaptive security appliance softwareversion unspecified
  • cpe cisco/secure firewall threat defenseversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-20013

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-20013

    30-day exploitation probability 0.3%

    first.org
  • NIST NVDVulnerability recordCVE-2026-20013

    A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device that may also impact the availability of services to devices elsewhere in the ne

    nvd.nist.gov

References