What is the CVSS score of CVE-2026-25108?

CVE-2026-25108 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 18.6%.

Is CVE-2026-25108 being actively exploited?

Yes, CVE-2026-25108 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, confirming active in-the-wild exploitation. Immediate patching is required.

How to fix or mitigate CVE-2026-25108?

Within 24 hours: Identify all systems running FileZen and assess whether the Antivirus Check Option is enabled; disable this feature immediately if possible and document the action. Within 7 days: Implement network segmentation to restrict FileZen system access to essential users only, deploy WAF rules to block suspicious HTTP requests to FileZen endpoints, and audit logs for exploitation attempts. Within 30 days: Contact FileZen for patch availability and timeline; establish a patching schedule; conduct a forensic review of FileZen systems for signs of compromise or unauthorized command execution.

Filezen CVE-2026-25108

HIGH

OS Command Injection (CWE-78)

2026-02-13 vultures@jpcert.or.jp

Command Injection Filezen Soliton

8.8

CVSS 3.1 · NVD

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Authenticate as valid user
Exploit

Send crafted HTTP request to antivirus endpoint
Execution

Inject OS command in parameter
Impact

Execute arbitrary command with FileZen process privileges

Vulnerability Assessment

Weakness	CWE CWE-78 OWASP Top 10:2025 A05:2025 - Injection ASVS 5.0 V1 - Encoding and Sanitization OS command sanitization, avoid shell exec MITRE ATT&CK 2 techniques across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Exploitation Conditions	FileZen Antivirus Check Option must be enabled. Attacker requires valid FileZen user credentials. Vulnerable HTTP endpoint must be accessible to authenticated users.
Impact	CVSS 8.8 (High). KEV-listed — actively exploited, particularly targeting Japanese organizations. EPSS 18.6%. Requires authentication (but many FileZen instances allow self-registration). Conditional on AV Check Option being enabled. Full command execution on appliance.
Exploit ScenarioDerived	An attacker authenticates to a FileZen instance (using compromised credentials or a self-registered account) and uploads a file with a specially crafted filename or content that injects OS commands into the antivirus scanning pipeline. The commands execute as the FileZen service account, providing shell access to the appliance. The attacker then accesses all stored files (potentially containing sensitive documents), establishes persistent backdoor access, and uses the appliance as a pivot point into the internal network.

Act Now Prioritize within 24-48h. Why: HIGH severity + EPSS > 10%.

Exploited in the wild (CISA KEV) No patch listed yet 18.6% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

FileZen contains an OS command injection vulnerability (CVE-2026-25108, CVSS 8.8) that allows authenticated users to execute arbitrary commands when the Antivirus Check Option is enabled. KEV-listed with EPSS 18.6%, this vulnerability in the Japanese file-sharing appliance has been actively exploited in campaigns targeting organizations in Japan and Asia-Pacific.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 22:02 CVSS 8.8

FileZen's antivirus scanning functionality contains an OS command injection vulnerability (CWE-78) that allows authenticated users to execute arbitrary system commands through specially crafted HTTP requests when the AV Check Option is enabled.

RemediationAI

Apply FileZen security update immediately. If unable to patch, disable the Antivirus Check Option temporarily. Restrict FileZen access to authorized networks. Audit uploaded files and user accounts for suspicious activity. Review stored files for potential data exposure.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

FileZen is a file-sharing appliance manufactured by Soliton Systems, widely deployed in Japanese government agencies and enterprises. When the antivirus check option is enabled, user-uploaded filenames or content is incorporated into OS commands for virus scanning without proper sanitization. An authenticated user can inject shell commands through crafted HTTP requests that are executed with the privileges of the FileZen service.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 8.8 HIGH

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Added to CISA KEV

Feb 24, 2026 - 21:38 cisa

CISA KEV

CIRCL Exploitation Confirmed

Feb 24, 2026 - 21:38 circl

CIRCL KEV

CVE Published

Feb 13, 2026 - 04:15 nvd

HIGH 8.8

DescriptionCVE.org

FileZen contains an OS command injection vulnerability. When FileZen Antivirus Check Option is enabled, a logged-in user may send a specially crafted HTTP request to execute an arbitrary OS command.

Executive ViewAI

Why It Matters

FileZen Antivirus contains a critical vulnerability (CVE-2026-25108) that allows authenticated users to execute arbitrary operating system commands on affected systems. This vulnerability is actively being exploited in the wild and poses an immediate risk to organizations using FileZen, potentially enabling attackers to compromise system integrity, steal data, or establish persistent access.

Business Impact: Severe

Compensating Controls

Disable FileZen Antivirus Check Option immediately if operationally feasible. Implement Web Application Firewall (WAF) rules to detect and block malicious HTTP requests containing OS command patterns (semicolons, pipes, backticks, $() syntax). Restrict network access to FileZen administrative interfaces using IP whitelisting and VPN requirements. Enable comprehensive logging and monitoring of FileZen HTTP requests and OS command execution. Require multi-factor authentication for all FileZen user accounts. Monitor CISA KEV and FileZen security advisories daily for patch release announcements.

Threat Intelligence Overview

EPSS Score

18.6%

Top 5% exploitable

CIRCL KEV

Listed

Community Exploited Vulnerability

Data Quality

4 sources

Confidence: Medium

NVD

CVE.org

CISA KEV

EPSS CIRCL

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV Yes

Public POC No

EPSS 18.6%

Patch available No

Active threat Yes

Deciding rule

HIGH severity + EPSS > 10%

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.