How severe is CVE-2026-20082?

CVE-2026-20082 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-20082 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-20082?

CVE-2026-20082 affects Cisco Adaptive Security Appliance Software. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-20082?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-20082 have an EU (EUVD) identifier?

Yes. CVE-2026-20082 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9471.

When was CVE-2026-20082 published?

CVE-2026-20082 was published on 2026-03-04 and last updated on 2026-06-17.

CVE-2026-20082

CVE-2026-20082 is a high-severity vulnerability in Cisco Adaptive Security Appliance Software with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-772.

Key facts

Severity: High (CVSS 3.x base score 8.6)
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-9471
Weakness: CWE-772
Affected product: Cisco Adaptive Security Appliance Software
Published: 2026-03-04
Last modified: 2026-06-17

Description

A vulnerability in the handling of the embryonic connection limits in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause incoming TCP SYN packets to be dropped incorrectly. This vulnerability is due to improper handling of new, incoming TCP connections that are destined to management or data interfaces when the device is under a TCP SYN flood attack. An attacker could exploit this vulnerability by sending a crafted stream of traffic to an affected device. A successful exploit could allow the attacker to prevent all incoming TCP connections to the device from being established, including remote management access, Remote Access VPN (RAVPN) connections, and all network protocols that are TCP-based. This results in a denial of service (DoS) condition for affected features.

Frequently asked questions

What is CVE-2026-20082?: A vulnerability in the handling of the embryonic connection limits in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause incoming TCP SYN packets to be dropped incorrectly. This vulnerability is due to improper handling of new, incoming TCP connections that are destined to management or data interfaces when the device is under a TCP SYN flood attack. An attacker could exploit this vulnerability by sending a crafted stream of traffic to an affected device. A successful exploit could allow the attacker to prevent all incoming TCP connections to the device from being established, including remote management access, Remote Access VPN (RAVPN) connections, and all network protocols that are TCP-based. This results in a denial of service (DoS) condition for affected features.
How severe is CVE-2026-20082?: CVE-2026-20082 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-20082 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-20082?: CVE-2026-20082 affects Cisco Adaptive Security Appliance Software. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-20082?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-20082 have an EU (EUVD) identifier?: Yes. CVE-2026-20082 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9471.
When was CVE-2026-20082 published?: CVE-2026-20082 was published on 2026-03-04 and last updated on 2026-06-17.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-dos-FCvLD6vR

Affected products (1)

cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*

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