CVE-2026-45158: opnsense Argument Injection — Fix

Description

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 underlying operating system. This vulnerability is fixed in 26.1.8.

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CVSS v3.1 Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0031

Probability of exploitation

0.54%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-88 CWE-88

Affected Products

Vendor	Product	Versions
opnsense	opnsense	< 26.1.8

References

Advisories & Patches

https://github.com/opnsense/core/security/advisories/GHSA-5rx3-w735-74wm

Frequently Asked Questions

What is CVE-2026-45158? +

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 underlying operating system. This vulnerability is fixed in 26.1.8. It has a CVSS v3.1 base score of 9.1 (CRITICAL).

How severe is CVE-2026-45158? +

CVE-2026-45158 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0031, placing it in the 1th percentile for exploitation probability.

What products are affected by CVE-2026-45158? +

CVE-2026-45158 affects products from opnsense, specifically: opnsense. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-45158? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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