CVE-2026-106931: EG Secure Solutions SiteGuard Server Edition OS Command Injection Vulnerability

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run EG Secure Solutions SiteGuard Server Edition. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-10-20, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-10-23; treat that as the outer limit, not the target.
• EPSS 1.4%, percentile 72: FIRST’s model estimates a 1.4% chance of exploitation activity in the next 30 days, higher than 72% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Needs local access needed. Lower urgency for most teams unless an attacker could already run code on the machine.
• Editorial verdict: Patch this week. SiteGuard WAF CVE-2026-106931: Exploited Command Injection — If you run SiteGuard Server Edition, save its diagnostic data and patch this week, sooner on public web servers; the bug is exploited, but its local rating means attackers need a foothold first.

What it is

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’s summary

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.

Weakness type: CWE-78.

Product: EG Secure Solutions SiteGuard Server Edition · Assigned by: jpcert · Published: 2026-10-14

Affected and fixed versions

Severity scores

• Attack vector: local access needed
• Attack complexity: low
• Attack requirements: none
• Privileges required: low (any account)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2026-10-20; federal due date 2026-10-23. Known ransomware use: Unknown.
• 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.
• CISA SSVC assessment: exploitation active, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 1.37% probability of exploitation activity in the next 30 days; percentile 72.

Timeline

• 2026-10-14 — CVE record published by jpcert
• 2026-10-14 — erroneo.us brief: SiteGuard WAF CVE-2026-106931: Exploited Command Injection
• 2026-10-20 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2026-10-21 — CVE record last updated
• 2026-10-23 — CISA remediation deadline for US federal agencies

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. Listed in CISA KEV notes (eg-secure.co.jp) eg-secure.co.jp

Vulnerability records

1. CVE.org record CVE-2026-106931 cve.org
2. NVD entry CVE-2026-106931 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov
2. Listed in CISA KEV notes (cisa.gov) cisa.gov
3. Listed in CISA KEV notes (cisa.gov) cisa.gov

Other references from the CVE record and advisory

1. jvn.jp jvn.jp

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