CVE-2026-106931
CVE-2026-106931 is a security flaw in EG Secure Solutions SiteGuard Server Edition. Attackers can run commands on EG Secure Solutions SiteGuard Server Edition. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 20 Oct 2026.[1]
EG Secure Solutions SiteGuard Server Edition is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Fixed in version Ver8.00 Update 5 and Ver7.00 Update 6.
Description
CISA calls it an OS command injection in EG Secure Solutions SiteGuard Server Edition. In its words: “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.”[1]
The underlying weakness is OS command injection (CWE-78), in MITRE’s list of common software weaknesses.[2]
It scores 8.5 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by the organisation that published the CVE using CVSS 4.0.[2]
Affected versions
NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]
| Product | Fixed in |
|---|---|
| SiteGuard Server Edition for Apache httpd | Ver8.00 Update 5 |
| SiteGuard Server Edition for Nginx | Ver8.00 Update 5 |
| SiteGuard Server Edition for IIS | Ver8.00 Update 5 |
| SiteGuard Server Edition for Apache httpd on FreeBSD | Ver7.00 Update 6 |
| SiteGuard Server Edition for Nginx on FreeBSD | Ver7.00 Update 6 |
Most families won’t have EG Secure Solutions SiteGuard Server Edition; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 20 Oct 2026, 6 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 23 Oct 2026 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 3%. That’s in the top 16% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
EG Secure Solutions has published a fix or advice.[3] CISA’s 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).”[1]
- Check whether you use it.EG Secure Solutions SiteGuard Server Edition is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed (fixed in version Ver8.00 Update 5 and Ver7.00 Update 6), or not in use. CISA gave US government agencies until 23 Oct 2026 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 8.5.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 3%.[4] |
See also
Other OS command injection flaws
- CVE-2026-110447, Collabora Online – Built-in CODE Server: online – built-in CODE server OS command injection ·
- CVE-2026-83549, SonicWall SMA1000 Appliances: OS command injection ·
- CVE-2026-49869, Kestra OSS: OSS OS command injection ·
- CVE-2026-73570, Synacor Zimbra Collaboration Suite (ZCS): OS command injection ·
- CVE-2026-16812, Arista VeloCloud Orchestrator: on-prem OS command injection ·
Added the same day
- CVE-2026-96656, Plex Media Server: external control of file name or path ·
- CVE-2026-96655, Plex Media Server: server-side request forgery (SSRF) ·
- CVE-2026-96654, Plex Media Server: improper neutralization of encoded URI schemes in a web page ·
- CVE-2026-96652, Plex Media Server: server-side request forgery (SSRF) ·
- CVE-2026-110936, Siemens Software Center: uncontrolled search path element ·
References
- ^ Cybersecurity and Infrastructure Security Agency. “EG Secure Solutions SiteGuard Server Edition OS Command Injection Vulnerability”. Known Exploited Vulnerabilities Catalog, added 20 Oct 2026.
- ^ National Institute of Standards and Technology. “CVE-2026-106931 Detail”. National Vulnerability Database, published 14 Oct 2026.
- ^ EG Secure Solutions. Advisories and fixes: eg-secure.co.jp.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.025, percentile 84.9, 31 Oct 2026.
- CVE Program. “CVE-2026-106931”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.