CVE-2026-20105
Memory Exhaustion DoS in Cisco ASA SSL VPN via Input Validation Flaw
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 functionality of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software.
It allows an authenticated, remote attacker who has a valid VPN connection to send specially crafted packets to the VPN server, which can cause the device to exhaust its memory.
As a result, the device may reload, causing a denial of service (DoS) condition.
This vulnerability arises because the system trusts user input without proper validation.
How can this vulnerability impact me? :
The primary impact of this vulnerability is a denial of service (DoS) condition on the affected device.
An attacker with valid VPN credentials can exploit this flaw to exhaust the device's memory, causing it to reload and become temporarily unavailable.
This can disrupt remote access services and potentially impact network security and availability.
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