Vulnerability in OPNsense (CVE-2026-45158)
Summary
Vulnerability in OPNsense (CVE-2026-45158). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 26.1.8 or later.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-45158 has been found in OPNsense.
Successful exploitation can lead to full system takeover. CVSS score: 9.1/10.
What to do: upgrade OPNsense to 26.1.8 or later.
If unsure, ask your IT team or search "OPNsense CVE-2026-45158" on the vendor's site.
CVE-2026-45158 (OPNsense) — CWE-88 / CVSS v3 9.1
Attack vector: remote (network-reachable) / no user interaction
Patched: 26.1.8 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-88) exists in OPNsense.
Check the vendor advisory for the affected versions of OPNsense.
Severity: Critical (CVSS 9.1/10). Successful exploitation can lead to full system takeover.
Update to 26.1.8.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'OPNsense' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'OPNsense' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
OPNsenseを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade OPNsense to 26.1.8ステージング環境で 26.1.8 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。