How severe is CVE-2026-45158?

CVE-2026-45158 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-45158 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-45158?

CVE-2026-45158 affects Opnsense. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-45158?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-45158 have an EU (EUVD) identifier?

Yes. CVE-2026-45158 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30202.

When was CVE-2026-45158 published?

CVE-2026-45158 was published on 2026-05-13 and last updated on 2026-06-17.

CVE-2026-45158

CVE-2026-45158 is a critical-severity vulnerability in Opnsense with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-88.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 1% (41st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-30202
Weakness: CWE-88
Affected product: Opnsense
Published: 2026-05-13
Last modified: 2026-06-17

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.

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.
How severe is CVE-2026-45158?: CVE-2026-45158 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-45158 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-45158?: CVE-2026-45158 affects Opnsense. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-45158?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-45158 have an EU (EUVD) identifier?: Yes. CVE-2026-45158 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30202.
When was CVE-2026-45158 published?: CVE-2026-45158 was published on 2026-05-13 and last updated on 2026-06-17.

References

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

Affected products (1)

cpe:2.3:a:opnsense:opnsense:*:*:*:*:*:*:*:*

More vulnerabilities in Opnsense

CVE-2023-27152 — Critical (CVSS 9.8): DECISO OPNsense 23.1 does not impose rate limits for authentication, allowing attackers to perform a brute-force attack…
CVE-2023-39008 — Critical (CVSS 9.8): A command injection vulnerability in the component /api/cron/settings/setJob/ of OPNsense Community Edition before 23.7…
CVE-2023-39004 — Critical (CVSS 9.8): Insecure permissions in the configuration directory (/conf/) of OPNsense Community Edition before 23.7 and Business…
CVE-2023-39001 — Critical (CVSS 9.8): A command injection vulnerability in the component diag_backup.php of OPNsense Community Edition before 23.7 and…
CVE-2023-39007 — Critical (CVSS 9.6): /ui/cron/item/open in the Cron component of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2…
CVE-2026-44194 — Critical (CVSS 9.1): OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.8, an authenticated Remote Code Execution…

All CVEs affecting Opnsense →

Other CWE-88 (Argument Injection) vulnerabilities

CVE-2026-57572 — Critical (CVSS 10.0): Crawl4AI is an open-source LLM-friendly web crawler and scraper. Prior to 0.9.0, the Docker API server accepted…
CVE-2026-40281 — Critical (CVSS 10.0): Gotenberg is a Docker-powered stateless API for PDF files. In versions 8.30.1 and earlier, the metadata write endpoint…
CVE-2023-6269 — Critical (CVSS 10.0): An argument injection vulnerability has been identified in the administrative web interface of the Atos Unify…
CVE-2007-0882 — Critical (CVSS 10.0): Argument injection vulnerability in the telnet daemon (in.telnetd) in Solaris 10 and 11 (SunOS 5.10 and 5.11)…
CVE-2004-0480 — Critical (CVSS 10.0): Argument injection vulnerability in IBM Lotus Notes 6.0.3 and 6.5 allows remote attackers to execute arbitrary code via…
CVE-1999-0113 — Critical (CVSS 10.0): Some implementations of rlogin allow root access if given a -froot parameter.

Browse all CWE-88 (Argument Injection) vulnerabilities →