Cyber Resilience

CVE-2026-20025

Memory Safety in Cisco Secure Firewall Threat Defense 6.4.0 – 7.0.9

Published
04 March 2026
Modified
11 August 2026
Patch / advisory
CVSS Score v3.1 6.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
EPSS Score 0.0016 6th percentile
Risk Priority 47 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-20025 is a medium-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Cisco Secure Firewall Threat Defense. Its CVSS base score is 6.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

A vulnerability in the OSPF protocol of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an authenticated, adjacent attacker to cause an affected device to reload unexpectedly, resulting in a DoS condition. To exploit this vulnerability,…

more

the attacker must have the OSPF secret key. This vulnerability is due to insufficient input validation when processing OSPF link-state update (LSU) packets. An attacker could exploit this vulnerability by sending crafted OSPF LSU packets. A successful exploit could allow the attacker to corrupt the heap, causing the device to reload, resulting in a DoS condition.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-20494Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20022Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20495Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20100Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20408Same product: Cisco Adaptive Security Appliance Software
CVE-2025-20333Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20020Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20049Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20402Same product: Cisco Adaptive Security Appliance Software
CVE-2024-20268Same product: Cisco Adaptive Security Appliance Software

Affected Assets

cisco
secure firewall threat defense
6.4.0 — 7.0.9 · 7.1.0 — 7.2.11 · 7.3.0 — 7.4.3
cisco
adaptive security appliance software
9.12.1 — 9.16.4.85 · 9.17.1 — 9.18.4.66 · 9.19.1 — 9.20.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.2.6

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (static analysis, fuzzing, unit tests) directly finds integer overflow defects before deployment.

Secure engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer overflow during calculation.

Input validation enforces bounds on values before arithmetic, stopping the conditions that trigger overflow or wraparound.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development can detect integer overflows before release.

prevents

Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.

degrades

Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.

degrades

Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.

prevents

Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.

References