Skip to main content

Cisco Secure Firewall EUVDEUVD-2026-81114

| CVE-2026-20335 HIGH
Incorrect Calculation (CWE-682)
2026-09-16 cisco GHSA-vcgm-f86r-xmp4
8.1
CVSS 3.1 · NVD
Share

Severity by source

Vendor (cisco) PRIMARY
HIGH
qualitative
NVD
8.1 HIGH
AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
vuln.today AI
8.1 HIGH

Agree with Cisco's shape: network-reachable and unauthenticated (AV:N/PR:N) but AC:H for the specific calculation trigger; C/I/A:H are vendor-asserted for this grouped hardening release.

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
4.0 AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (cisco).

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

2
Analysis Generated
Sep 16, 2026 - 21:40 vuln.today
CVE Published
Sep 16, 2026 - 20:10 nvd
HIGH 8.1

DescriptionNVD

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense Software and Cisco Secure Firewall Management Center Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities.

The vulnerabilities tracked by CVE-2026-20335 are related to incorrect calculation issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-682.

AnalysisAI

Multiple internally discovered incorrect-calculation flaws in Cisco Secure Firewall ASA Software, Secure Firewall Threat Defense (FTD) Software, and Secure Firewall Management Center (FMC) Software can be triggered by remote, unauthenticated attackers over the network and may result in high confidentiality, integrity, and availability impact across affected firewalls and their management plane. Cisco rates the group at CVSS 8.1 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H), but the vector's AC:H reflects that exploitation depends on attacker-uncontrolled conditions - reliably producing the precise malformed input that causes the miscalculation is the practical barrier, and the bundled advisory names no single feature, protocol, or configuration toggle as a prerequisite. …

Unlock full vulnerability intelligence

  • Risk assessment & exploitation conditions
  • Attack chain visualization
  • Remediation with exact patch versions
  • Threat intelligence from 22 sources
  • Personal watchlist & email alerts

Free forever · No credit card required

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access
technique details hidden
Delivery
technique details hidden
Exploit
technique details hidden
Execution
technique details hidden
Impact
technique details hidden

Vulnerability AssessmentAI

Exploitation Exploitation requires network reachability to a Cisco Secure ASA, FTD, or FMC device and no authentication (PR:N), but the CVSS vector marks AC:H - meaning success depends on specific, attacker-uncontrolled conditions inherent to the incorrect-calculation flaw (e.g. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment The vendor scores this 8.1 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H). … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario Full exploit scenario with step-by-step reproduction available after sign-in.
Remediation Apply the software hardening release from Cisco that specifically addresses CVE-2026-20335; because Cisco shipped these fixes as a bundled internal-review hardening update, patch availability is confirmed per vendor advisory rather than by a single published fix version, and administrators should consult the Cisco advisory at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-asaftdfmc-uvpPROhN to identify the exact fixed build for each ASA 9.16/9.18/9.20/9.22/9.23/9.24, FTD 7.0/7.3/7.4/7.6/7.7/10.0, and FMC 7.0/7.2/7.3/7.4/7.6/7.7/10.0 branch in use, since Cisco typically publishes per-train fixed releases instead of a single global version. … Detailed patch versions, workarounds, and compensating controls in full report.

Recommended ActionAI

Within 24 hours, inventory all instances of Cisco Secure Firewall ASA, FTD, and FMC software and restrict management plane access to trusted internal networks only, ensuring that remote management is disabled or tightly controlled. …

Sign in for detailed remediation steps and compensating controls.

Threat intelligence, references, and detailed analysis are available after sign-in.

CVE-2026-20332 CRITICAL
9.9 Sep 16

Improper access control defects in Cisco Secure Firewall ASA, FTD, and FMC software allow an authenticated, low-privileg

CVE-2026-20330 CRITICAL
9.9 Sep 16

Multiple improper neutralization flaws in Cisco Secure Firewall ASA, Threat Defense (FTD), and Management Center (FMC) s

CVE-2026-20329 CRITICAL
9.9 Sep 16

Improper handling of exceptional conditions across Cisco Secure Firewall ASA Software, Threat Defense (FTD) Software, an

CVE-2026-20333 HIGH
8.8 Sep 16

A hardening release for Cisco Secure Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (F

CVE-2026-20336 HIGH
8.8 Sep 16

Unauthenticated attackers on an adjacent network segment can exploit multiple resource lifetime flaws (CWE-664) in Cisco

CVE-2026-20154 HIGH
8.6 Sep 16

Sustained TCP SYN floods directed at Cisco Secure Firewall ASA and FTD devices can drive the appliance into high CPU uti

CVE-2026-20249 HIGH
8.6 Sep 16

Unauthenticated remote attackers can crash the IKEv2 process on Cisco Secure Firewall ASA and FTD software configured fo

CVE-2026-20250 HIGH
8.6 Sep 16

Unauthenticated, remote denial of service affecting Cisco Secure Firewall Adaptive Security Appliance (ASA) and Threat D

CVE-2026-20334 HIGH
8.4 Sep 16

Multiple internally-discovered coding-standard defects in Cisco Secure Firewall ASA Software, Threat Defense (FTD) Softw

CVE-2026-20222 HIGH
7.4 Sep 16

Denial of service in Cisco Secure Firewall ASA and FTD Software allows a network-adjacent, unauthenticated attacker to r

CVE-2026-20248 MEDIUM
6.8 Sep 16

Cisco Secure Firewall ASA and FTD software contain a logic error in the DNS over TCP response handler that can be trigge

CVE-2026-20120 MEDIUM
5.8 Sep 16

Access-control bypass in Cisco Secure Firewall ASA and Threat Defense (FTD) software allows an unauthenticated, remote a

Share

EUVD-2026-81114 vulnerability details – vuln.today

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy