Cyber Resilience

CVE-2026-20022

Cisco Adaptive Security Appliance Software 9.12.1 … 9.23.1.7

Published
04 March 2026
Modified
04 May 2026
Patch / advisory
CVSS Score v3.1 6.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS Score 0.0019 9th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-20022 is a medium-severity Use of Out-of-range Pointer Offset (CWE-823) vulnerability in Cisco Adaptive Security Appliance Software. Its CVSS base score is 6.1 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 9th 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 CM-7 (Least Functionality) and SI-2 (Flaw Remediation) — 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 unauthenticated, adjacent attacker to cause an affected device to reload unexpectedly, resulting in a DoS condition when OSPF canonicalization debug…

more

is enabled by using the command debug ip ospf canon. This vulnerability is due to insufficient input validation when processing OSPF LSU packets. An attacker could exploit this vulnerability by sending crafted unauthenticated OSPF packets. A successful exploit could allow the attacker to write to memory outside of the packet data, causing the device to reload, resulting in a DoS condition.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

CVE enables direct DoS via crafted OSPF packet exploitation of input validation flaw (CWE-823) causing device reload.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-20025Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20021Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20101Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20014Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20049Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20105Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20023Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20103Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20039Same product: Cisco Adaptive Security Appliance Software
CVE-2026-20013Same product: Cisco Adaptive Security Appliance Software

Affected Assets

cisco
adaptive security appliance software
9.12.1, 9.12.1.2, 9.12.1.3, 9.12.2, 9.12.2.1
cisco
firepower threat defense software
6.4.0, 6.4.0.1, 6.4.0.10, 6.4.0.11, 6.4.0.12

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-2 Flaw Remediation
  • CM-7 Least Functionality
  • SC-7 Boundary Protection
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V1.4.1

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires applying vendor patches that eliminate the insufficient input validation flaw in OSPF LSU processing.

prevent

Least functionality disables the non-essential debug ip ospf canon command that must be enabled for the memory corruption to occur.

prevent

Boundary protection can restrict unauthenticated adjacent OSPF traffic and limit exposure to crafted LSU packets on the link.

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 bounds-checked pointer arithmetic and static analysis to prevent out-of-range offsets.

ID.RA-01 partial match
prevents

SAST/DAST tools used for vulnerability identification can surface this class of coding defect.

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.

detects

Security testing can detect out-of-range pointer offsets before release.

prevents

Secure SDLC mandates input validation and bounds checking that can prevent out-of-range pointer offsets.

prevents

Application security requirements include memory-safety rules that reduce pointer-offset errors.

degrades

Secure architecture principles promote safe pointer handling and memory layout controls.

prevents

Secure coding standards directly forbid unsafe pointer arithmetic and require bounds checks.

References