Cyber Resilience

CVE-2026-45158

Opnsense ≤ 26.1.8

Published
13 May 2026
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 9.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0053 42th percentile
Risk Priority 59 floored blend · peak EPSS

Summary

CVE-2026-45158 is a critical-severity Argument Injection (CWE-88) vulnerability in Opnsense Opnsense. Its CVSS base score is 9.1 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked at the 42th 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 SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.8, unsanitized user input is passed to the DHCP configuration of the configured interface, which is processed by a shell script, allowing remote code execution as root on the…

more

underlying operating system. This vulnerability is fixed in 26.1.8.

CWE(s)
CWE-88

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
attack.mitre.org →
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
attack.mitre.org →
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
attack.mitre.org →
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-44193Same product: Opnsense Opnsense
CVE-2026-44194Same product: Opnsense Opnsense
CVE-2023-39008Same product: Opnsense Opnsense
CVE-2023-39001Same product: Opnsense Opnsense
CVE-2025-50989Same product: Opnsense Opnsense
CVE-2023-39005Same product: Opnsense Opnsense
CVE-2023-44276Same product: Opnsense Opnsense
CVE-2023-39002Same product: Opnsense Opnsense
CVE-2023-38999Same product: Opnsense Opnsense
CVE-2023-39007Same product: Opnsense Opnsense

Affected Assets

opnsense
opnsense
≤ 26.1.8

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)
  • V1.2.5

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing can discover argument-injection flaws in command-construction code but does not stop their introduction.

SI-10 Information Input Validation good match

Input validation directly stops construction of command strings containing unneutralized delimiters or injected arguments.

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 proper input validation and command construction to prevent argument injection.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect argument injection but does not prevent it at the source.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates input validation and command construction practices that directly prevent argument injection.

A.8.26 Application security requirements partial match
prevents

Application security requirements include explicit rules for safe command-line argument handling and escaping.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles discourage unsafe command invocation patterns and favor safer APIs.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly require proper neutralization of command arguments, directly eliminating CWE-88.

A.8.32 Change management none match
none

Change management can catch unsafe command patterns during reviews but is not a direct mitigation.

References