VulnerabilityPublished 4 Mar 2026

CVE-2026-20014: Cisco Secure Firewall Adaptive Security Appliance (ASA) Software · Memory Leak

Affects Cisco Secure Firewall Adaptive Security Appliance (ASA) SoftwareSource CVE Database V5

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Not known to be exploited · CVSS 7.7 High.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

7.7High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Changed
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
CiscoCisco Secure Firewall Adaptive Security Appliance (ASA) Software	Affected 9.18.1 – 9.23.1.13 68 affected builds	Fixed in–
CiscoCisco Secure Firewall Threat Defense (FTD) Software	Affected 7.2.0 – 7.7.10.1 36 affected builds	Fixed in–

AI-suggested

Apply official Cisco patches or software updates as soon as they become available for the affected ASA/FTD versions. Regularly monitor Cisco security advisories for updates on this vulnerability.
Restrict VPN user access and enforce strong authentication mechanisms to reduce the risk of credential compromise, as exploitation requires valid VPN credentials.
Implement network segmentation and firewall redundancy (e.g., high availability pairs) to minimize service disruption during device reloads.
Monitor VPN and firewall logs for unusual or repeated IKEv2 packet activity that could indicate exploitation attempts.
Consider deploying rate limiting or traffic anomaly detection on VPN connections to detect and block abnormal IKEv2 packet patterns.
Conduct regular audits of VPN user accounts and promptly disable unused or suspicious accounts to limit attacker access.
If patching is delayed, consider temporarily disabling IKEv2 VPN features if operationally feasible or restricting VPN access to trusted IP ranges to reduce exposure.
Educate network security teams about this vulnerability to ensure rapid detection and response to potential exploitation attempts.

Description

A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an authenticated, remote attacker with valid VPN user credentials 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 the improper processing of IKEv2 packets. An attacker could exploit this vulnerability by sending crafted, authenticated IKEv2 packets to an affected device. A successful exploit could allow the attacker to exhaust memory, causing the device to reload.

Impact

The primary impact of CVE-2026-20014 is a denial-of-service condition on Cisco Secure Firewall ASA and FTD devices, which are widely deployed as perimeter security and VPN gateways in enterprise and service provider networks globally. Successful exploitation can cause the firewall to reload, interrupting VPN connectivity and firewall protections. This disruption can lead to temporary loss of network access for remote users, degraded security posture, and potential cascading effects on internal network availability if firewall failover or redundancy is not properly configured. Organizations relying heavily on Cisco ASA/FTD for secure remote access and perimeter defense may experience significant operational impact, including business continuity interruptions and increased exposure to other threats during downtime. The requirement for valid VPN credentials limits exploitation to insiders or compromised accounts, but the ease of triggering the DoS once authenticated makes it a potent tool for attackers aiming to disrupt network operations. The broad range of affected software versions increases the number of vulnerable deployments worldwide. No confidentiality or integrity impact is indicated, but availability impact is high, which is critical for network security infrastructure.

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ikev2-dos-eBueGdEG (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Mar 2026, 20:06 UTC

Technical details

References

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