According to its self-reported version, Cisco IOS is affected by multiple vulnerabilities.

  - A vulnerability in the IKEv2 feature of Cisco IOS Software, IOS XE Software, Secure Firewall ASA     Software, and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to     reload, resulting in a DoS condition. This vulnerability is due to the improper processing of IKEv2     packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected     device. A successful exploit could allow the attacker to cause an infinite loop that exhausts resources     and could cause the device to reload. (CVE-2025-20253)

  - A vulnerability in the Internet Key Exchange Version 2 (IKEv2) feature of Cisco IOS Software, IOS XE     Software, Secure Firewall Adaptive Security Appliance (ASA) Software, and 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. This vulnerability is due to a lack of proper processing of IKEv2     packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected     device. In the case of Cisco IOS and IOS XE Software, a successful exploit could allow the attacker to     cause the device to reload unexpectedly. In the case of Cisco ASA and FTD Software, a successful exploit     could allow the attacker to partially exhaust system memory, causing system instability such as being     unable to establish new IKEv2 VPN sessions. A manual reboot of the device is required to recover from     this condition. (CVE-2025-20225, CVE-2025-20239)

Please see the included Cisco BIDs and Cisco Security Advisory for more information.

According to its self-reported version, Cisco ASA Software is affected by multiple vulnerabilities.

  - A vulnerability in the IKEv2 feature of Cisco IOS Software, IOS XE Software, Secure Firewall ASA     Software, and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to     reload, resulting in a DoS condition. This vulnerability is due to the improper processing of IKEv2     packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected     device. A successful exploit could allow the attacker to cause an infinite loop that exhausts resources     and could cause the device to reload. (CVE-2025-20253)

  - A vulnerability in the Internet Key Exchange Version 2 (IKEv2) feature of Cisco IOS Software, IOS XE     Software, Secure Firewall Adaptive Security Appliance (ASA) Software, and 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. This vulnerability is due to a lack of proper processing of IKEv2     packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected     device. In the case of Cisco IOS and IOS XE Software, a successful exploit could allow the attacker to     cause the device to reload unexpectedly. In the case of Cisco ASA and FTD Software, a successful exploit     could allow the attacker to partially exhaust system memory, causing system instability such as being     unable to establish new IKEv2 VPN sessions. A manual reboot of the device is required to recover from     this condition. (CVE-2025-20225, CVE-2025-20239)

  - A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco Secure Firewall Adaptive     Security Appliance (ASA) Software and 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. This vulnerability is due to improper parsing of IKEv2 packets. An attacker could exploit this     vulnerability by sending a continuous stream of crafted IKEv2 packets to an affected device. A successful     exploit could allow the attacker to partially exhaust system memory, causing system instability like being     unable to establish new IKEv2 VPN sessions. A manual reboot of the device is required to recover from     this condition. (CVE-2025-20224, CVE-2025-20252, CVE-2025-20254)

Please see the included Cisco BIDs and Cisco Security Advisory for more information.

According to its self-reported version, Cisco IOS-XE Software is affected by multiple vulnerabilities.

  - A vulnerability in the IKEv2 feature of Cisco IOS Software, IOS XE Software, Secure Firewall ASA     Software, and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to     reload, resulting in a DoS condition. This vulnerability is due to the improper processing of IKEv2     packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected     device. A successful exploit could allow the attacker to cause an infinite loop that exhausts resources     and could cause the device to reload. (CVE-2025-20253)

  - A vulnerability in the Internet Key Exchange Version 2 (IKEv2) feature of Cisco IOS Software, IOS XE     Software, Secure Firewall Adaptive Security Appliance (ASA) Software, and 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. This vulnerability is due to a lack of proper processing of IKEv2     packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected     device. In the case of Cisco IOS and IOS XE Software, a successful exploit could allow the attacker to     cause the device to reload unexpectedly. In the case of Cisco ASA and FTD Software, a successful exploit     could allow the attacker to partially exhaust system memory, causing system instability such as being     unable to establish new IKEv2 VPN sessions. A manual reboot of the device is required to recover from     this condition. (CVE-2025-20225, CVE-2025-20239)

Please see the included Cisco BIDs and Cisco Security Advisory for more information.

According to its self-reported version, Cisco Secure Firewall Threat Defense (FTD) Software is affected by multiple vulnerabilities.

  - A vulnerability in the IKEv2 feature of Cisco IOS Software, IOS XE Software, Secure Firewall ASA     Software, and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to     reload, resulting in a DoS condition. This vulnerability is due to the improper processing of IKEv2     packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected     device. A successful exploit could allow the attacker to cause an infinite loop that exhausts resources     and could cause the device to reload. (CVE-2025-20253)

  - A vulnerability in the Internet Key Exchange Version 2 (IKEv2) feature of Cisco IOS Software, IOS XE     Software, Secure Firewall Adaptive Security Appliance (ASA) Software, and 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. This vulnerability is due to a lack of proper processing of IKEv2     packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected     device. In the case of Cisco IOS and IOS XE Software, a successful exploit could allow the attacker to     cause the device to reload unexpectedly. In the case of Cisco ASA and FTD Software, a successful exploit     could allow the attacker to partially exhaust system memory, causing system instability such as being     unable to establish new IKEv2 VPN sessions. A manual reboot of the device is required to recover from     this condition. (CVE-2025-20225, CVE-2025-20239)

  - A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco Secure Firewall Adaptive     Security Appliance (ASA) Software and 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. This vulnerability is due to improper parsing of IKEv2 packets. An attacker could exploit this     vulnerability by sending a continuous stream of crafted IKEv2 packets to an affected device. A successful     exploit could allow the attacker to partially exhaust system memory, causing system instability like being     unable to establish new IKEv2 VPN sessions. A manual reboot of the device is required to recover from     this condition. (CVE-2025-20224, CVE-2025-20252, CVE-2025-20254)

Please see the included Cisco BIDs and Cisco Security Advisory for more information.

ID	Name	Product	Family	Published	Updated	Severity
331354	Cisco IOS Software IKEv2 Multiple Vulnerabilities (cisco-sa-asa-ftd-ios-dos-DOESHWHy)	Nessus	CISCO	7/31/2026	8/7/2026	high
331353	Cisco Adaptive Security Appliance (ASA) Software IKEv2 Multiple Vulnerabilities (cisco-sa-asa-ftd-ios-dos-DOESHWHy)	Nessus	CISCO	7/31/2026	8/7/2026	high
331356	Cisco IOS XE Software IKEv2 Multiple Vulnerabilities (cisco-sa-asa-ftd-ios-dos-DOESHWHy)	Nessus	CISCO	7/31/2026	8/7/2026	high
331355	Cisco Firepower Threat Defense (FTD) Software IKEv2 Multiple Vulnerabilities (cisco-sa-asa-ftd-ios-dos-DOESHWHy)	Nessus	CISCO	7/31/2026	8/7/2026	high

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