> Source: [sk184715](https://support.checkpoint.com/results/sk/sk184715)

# sk184715 - Zero Phishing blade does not inject zp.js or block phishing sites for VPN-decrypted traffic on a VSX VSLS Cluster

| Property | Value |
|----------|-------|
| Solution ID | sk184715 |
| Date Created | 2026-02-19 |
| Last Modified | 2026-03-05 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R82.10, R82, R81.20, R81.10 (EOS) |
| OS | Gaia |

## Symptoms

- * Zero Phishing Blade does not inject the *zp.js* file or block phishing websites for VPN-decrypted traffic on a Check Point VSX VSLS cluster.   

  Environment:

  * HTTPS Inspection is enabled
  * The Zero Phishing process is running and the portal is accessible
  * Threat Prevention and other blades (for example, Anti-Virus, Threat Emulation, Threat Extraction, URL Filtering) function as expected, including VPN traffic.
  * The `disable_strict_hold_on_external_zone` kernel parameter is set to 1 on the Security Gateway.

  <br />

* No errors or warnings appear in logs related to Zero Phishing or HTTPS Inspection.

* Running the `fw ctl debug -m CI + all` debug command generates output which shows that traffic is treated as belonging to an external zone after VPN decryption, even though ports are marked as internal.

## Cause

When the kernel parameter `disable_strict_hold_on_external_zone` is set to 1 on the Security Gateway, strict hold is disabled for traffic classified as **External** or **VPN** .   
This prevents the Zero Phishing blade from performing in-browser injection for VPN-decrypted traffic. As a result, the Zero Phishing blade does not inject the *zp.js* file, and does not block phishing sites in the browser for VPN users.  
Threat Prevention blades (such as Threat Emulation and Threat Extraction) do not rely on strict hold for in-browser injection and continue to function as expected.

## Solution

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