CVE-2026-20106
Memory Exhaustion DoS in Cisco ASA SSL VPN and HTTP Management
Publication date: 2026-03-04
Last updated on: 2026-04-16
Assigner: Cisco Systems, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| cisco | adaptive_security_appliance_software | From 9.12.1 (inc) to 9.16.4.85 (exc) |
| cisco | adaptive_security_appliance_software | From 9.17.1 (inc) to 9.18.4.66 (exc) |
| cisco | adaptive_security_appliance_software | From 9.19.1 (inc) to 9.20.4 (exc) |
| cisco | adaptive_security_appliance_software | From 9.22.1.1 (inc) to 9.22.2.4 (exc) |
| cisco | adaptive_security_appliance_software | From 9.23.1 (inc) to 9.23.1.7 (exc) |
| cisco | firepower_threat_defense_software | From 6.4.0 (inc) to 7.0.9 (exc) |
| cisco | firepower_threat_defense_software | From 7.1.0 (inc) to 7.2.11 (exc) |
| cisco | firepower_threat_defense_software | From 7.3.0 (inc) to 7.4.3 (exc) |
| cisco | firepower_threat_defense_software | From 7.6.0 (inc) to 7.6.4 (exc) |
| cisco | firepower_threat_defense_software | From 7.7.0 (inc) to 7.7.11 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-401 | The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the Remote Access SSL VPN, HTTP management, and MUS functionality of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software.
It occurs because the software trusts user input without proper validation. An unauthenticated, remote attacker can exploit this by sending specially crafted packets to the Remote Access SSL VPN server.
Successful exploitation can exhaust the device's memory, causing it to stop responding and resulting in a denial of service (DoS) condition that requires a manual reboot.
How can this vulnerability impact me? :
This vulnerability can impact you by allowing an unauthenticated remote attacker to cause a denial of service (DoS) on your Cisco Secure Firewall device.
The attacker can exhaust the device's memory, making it stop responding and forcing a manual reboot to restore functionality.
During this downtime, network security protections provided by the device may be unavailable, potentially exposing your network to additional risks.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know