CVE Tools
Sign in

CVE-2026-20073

Cisco Secure Firewall Adaptive Security Appliance Software and Cisco Secure Firewall Threat Defense Software Access Control List Bypass Vulnerability

Published: Mar 4, 2026Updated: May 4, 2026 Sources: CVE List NVDCWE-284
NVD MITRE
5.8CVSSMEDIUM
EPSS Score
0.4%
Top 70.3%
CISA KEV
Not in KEV
Exploits
0 Known
Remediation
Patch Available

Description

A vulnerability in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to send traffic that should be denied through an affected device. This vulnerability is due to improper error handling when an affected device that is joining a cluster runs out of memory while replicating access control rules. An attacker could exploit this vulnerability by sending traffic that should be blocked through the device. A successful exploit could allow the attacker to bypass access controls and reach devices in protected networks.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:CC:NI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:CScope
Changed
Impact
C:NConfidentiality
None
I:LIntegrity
Low
A:NAvailability
None
Open in CVSS calculator →

Weaknesses

CWE-284NVD-CWE-noinfo

Affected Products

adaptive security appliance softwarecisco
On-premNetwork Device
Networking Infrastructure / firewall
firepower threat defensecisco
On-premSecurity Product
Networking Infrastructure / firewall
Cisco Secure Firewall Adaptive Security Appliance (ASA) SoftwareCisco
EmbeddedOS
Networking Infrastructure / firewall
Cisco Secure Firewall Threat Defense (FTD) SoftwareCisco
On-premSecurity Product
Security Products
ciscocommercialUSNetworking Infrastructureaka cisco systems, cisco systems inc.

Exploitability

0 exploit sources identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-aclbypass-dos-CVxVRSvQ
sec.cloudapps.cisco.com

Timeline

Published
Mar 4, 2026
Last Updated
May 4, 2026

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-20073 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows