Hackers are actively exploiting a critical flaw in SiteGuard Server Edition, a web application firewall used on many websites, to take full control of affected servers. The bug, CVE-2026-106931, is an OS command-injection issue in the statistics feature, which is enabled by default. It affects SiteGuard Server Edition for Apache httpd, Nginx, and IIS versions 2.20 and later before 8.00 Update 5, plus FreeBSD Apache/Nginx builds before 7.00 Update 6; IIS editions 3.10 through 4.00 Update 4 are not affected.
Why it matters: Organizations using SiteGuard Server Edition should treat this as urgent because active exploitation can give attackers highest-level control of the server. Update or apply the vendor patch immediately, and preserve diagnostic data first because remediation may erase evidence of compromise.
Bill Toulas
2026.10.18
100% relevant
This article establishes a distinct new story: a newly tracked, actively exploited SiteGuard Server Edition vulnerability with vendor and JPCERT warnings, affected version ranges, and emergency remediation guidance.
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