--- id: "CVE-2026-106931" kind: "vulnerability" aliases: ["CVE-2026-106931"] title: "e-guardian siteguard: SiteGuard Server Edition contains an OS command injection vulnerability, which may allow an attacker to execute\u2026" severity: "critical" cvss: 8.5 epss: null exploited: true status: "open" category: "infrastructure" products: [{"name": "EG Secure Solutions SiteGuard Server Edition", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "SiteGuard Server Edition (Apache, Nginx, IIS)", "fixed": ["8.00 Update5"], "affected": ">= 2.20, < 8.00 Update5 (IIS 3.10 to 4.00 Update4 not affected)", "ecosystem": "vendor"}, {"name": "SiteGuard Server Edition (FreeBSD Apache, Nginx)", "fixed": ["7.00 Update6"], "affected": ">= 2.20, < 7.00 Update6", "ecosystem": "vendor"}, {"name": "e-guardian siteguard", "fixed": ["8.00"], "affected": ">= 2.20, < 8.00", "ecosystem": "vendor"}, {"name": "e-guardian siteguard", "fixed": [], "affected": "= 8.00", "ecosystem": "vendor"}, {"name": "e-guardian siteguard", "fixed": ["7.00"], "affected": ">= 2.20, < 7.00", "ecosystem": "vendor"}, {"name": "e-guardian siteguard", "fixed": [], "affected": "= 7.00", "ecosystem": "vendor"}, {"name": "e-guardian siteguard", "fixed": ["3.10"], "affected": ">= 2.20, < 3.10", "ecosystem": "vendor"}, {"name": "e-guardian siteguard", "fixed": ["8.00"], "affected": ">= 4.10, < 8.00", "ecosystem": "vendor"}] ecosystems: ["vendor"] tags: ["apache", "eg-secure-solutions", "exploited", "freebsd", "iis", "infrastructure", "linux", "nginx", "self-hosted", "siteguard", "waf", "windows"] not_affected_if: ["iis-3.10-to-4.00-update4"] published_at: "2026-10-14T05:16:42+00:00" first_seen_at: "2026-10-23T19:11:50+00:00" updated_at: "2026-10-23T23:44:52+00:00" sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-106931", "first_seen_at": "2026-10-23T19:11:50+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-23T20:21:05+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-106931", "first_seen_at": "2026-10-23T23:44:52+00:00"}] --- # e-guardian siteguard: SiteGuard Server Edition contains an OS command injection vulnerability, which may allow an attacker to execute… EG Secure Solutions SiteGuard Server Edition, a web application firewall module for Apache, Nginx and IIS, has an OS command injection flaw. An attacker can run arbitrary operating system commands with root or SYSTEM privileges on the host. _Summary, check and fix written by a model from the sources; labelled as such._ ## Affected - vendor:EG Secure Solutions SiteGuard Server Edition affected ? fixed ? - vendor:SiteGuard Server Edition (Apache, Nginx, IIS) affected >= 2.20, < 8.00 Update5 (IIS 3.10 to 4.00 Update4 not affected) fixed 8.00 Update5 - vendor:SiteGuard Server Edition (FreeBSD Apache, Nginx) affected >= 2.20, < 7.00 Update6 fixed 7.00 Update6 - vendor:e-guardian siteguard affected >= 2.20, < 8.00 fixed 8.00 - vendor:e-guardian siteguard affected = 8.00 fixed ? - vendor:e-guardian siteguard affected >= 2.20, < 7.00 fixed 7.00 - vendor:e-guardian siteguard affected = 7.00 fixed ? - vendor:e-guardian siteguard affected >= 2.20, < 3.10 fixed 3.10 - vendor:e-guardian siteguard affected >= 4.10, < 8.00 fixed 8.00 ## How to check Check the installed SiteGuard Server Edition version against the affected ranges: 2.20 up to 8.00 Update5 for Apache, Nginx and IIS, and 2.20 up to 7.00 Update6 for FreeBSD Apache and Nginx. IIS 3.10 to 4.00 Update4 is not affected. ## Fix Upgrade to 8.00 Update5, or to 7.00 Update6 on FreeBSD Apache and Nginx. Apply mitigations per vendor instructions, and if none are available, discontinue use of the product per CISA guidance. ## Timeline - 2026-10-23T19:11:50+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-106931 - 2026-10-23T20:21:05+00:00 analyst — Vendor alert (EG Secure Solutions, 2026-10-14), JVN#88474777 and JPCERT/CC confirm affected/fixed versions and in-the-wild exploitation; no public PoC or IOC list found; CVSS 4.0 8.5 / 3.0 7.8 (local vector per vendor), severity left unchanged. - 2026-10-23T23:44:52+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-106931 ## Documents - [advisory] EG Secure Solutions: SiteGuard Server Edition OS command injection (urgent) https://www.eg-secure.co.jp/siteguard/news/alert-202610-1 - [advisory] JVN#88474777 SiteGuard Server Edition OS command injection http://jvn.jp/en/jp/JVN88474777/index.html - [describes] JPCERT/CC alert on CVE-2026-106931 https://www.jpcert.or.jp/at/2026/at260032.html - [discussion] BleepingComputer: Hackers exploit SiteGuard WAF flaw https://www.bleepingcomputer.com/news/security/hackers-exploit-siteguard-waf-flaw-to-run-commands-as-system-root/ ## From the sources EG Secure Solutions SiteGuard Server Edition contains an OS command injection vulnerability which may allow an attacker to execute arbitrary OS commands with root or SYSTEM privileges on the system running the affected product. CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. --- _Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_