How to fix CVE-2019-25374?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

Is PHP affected by CVE-2019-25374?

Organizations using OPNsense 19.1 should be aware of moderate risk from CVE-2019-25374, a cross-site scripting vulnerability rated CVSS 6.1. Attackers could inject scripts to steal sessions or perform actions as authenticated users. Proof-of-concept code is publicly available.

CVE-2019-25374

MEDIUM

2026-02-15 [email protected]

6.1

CVSS 3.1

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

PoC Detected

Feb 18, 2026 - 19:12 vuln.today

Public exploit code

CVE Published

Feb 15, 2026 - 14:16 nvd

MEDIUM 6.1

Description

OPNsense 19.1 contains a reflected cross-site scripting vulnerability that allows attackers to inject malicious scripts by exploiting the passthrough_networks parameter in vpn_ipsec_settings.php. Attackers can craft POST requests with JavaScript payloads in the passthrough_networks parameter to execute arbitrary code in users' browsers.

Analysis

Technical Context

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects the passthrough_networks component of Opnsense. OPNsense 19.1 contains a reflected cross-site scripting vulnerability that allows attackers to inject malicious scripts by exploiting the passthrough_networks parameter in vpn_ipsec_settings.php. Attackers can craft POST requests with JavaScript payloads in the passthrough_networks parameter to execute arbitrary code in users' browsers.

Affected Products

Vendor: Opnsense. Product: Opnsense. Versions: up to 19.1. Component: passthrough_networks.

Remediation

Monitor vendor advisories for a patch. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.

Priority Score

Low Medium High Critical

KEV: 0

EPSS: +0.0

CVSS: +30

POC: +20

CVE-2019-25374 vulnerability details – vuln.today

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CVE-2019-25374

CVSS Vector

Lifecycle Timeline

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CVE-2019-25374

CVSS Vector

Lifecycle Timeline

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Description

Analysis

Technical Context

Affected Products

Remediation

Priority Score

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External POC / Exploit Code