CVE-2026-1708 – This vulnerability allows unauthenticated attac... (How to Fix)

Q: What is the severity of CVE-2026-1708?

CVE-2026-1708 has a CVSS score of 7.5 (HIGH). This vulnerability allows unauthenticated attackers to perform blind SQL injection attacks on WordPress sites using the Simply Schedule Appointments plugin. Attackers can extract sensitive database information by sending malicious JSON payloads containing SQL commands. All WordPress sites using this plugin up to version 1.6.9.27 are affected.

📋 TL;DR

This vulnerability allows unauthenticated attackers to perform blind SQL injection attacks on WordPress sites using the Simply Schedule Appointments plugin. Attackers can extract sensitive database information by sending malicious JSON payloads containing SQL commands. All WordPress sites using this plugin up to version 1.6.9.27 are affected.

💻 Affected Systems

Products:

Simply Schedule Appointments Booking Plugin for WordPress

Versions: All versions up to and including 1.6.9.27

Operating Systems: All operating systems running WordPress

Default Config Vulnerable: ⚠️ Yes

Notes: Requires the attacker to obtain a valid public_token which is exposed during normal booking operations.

⚠️ Manual Verification Required

This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.

Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).

🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.

Recommended Actions:

Review the CVE details at NVD
Check vendor security advisories for your specific version
Test if the vulnerability is exploitable in your environment
Consider updating to the latest version as a precaution

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete database compromise including user credentials, personal data, and administrative access leading to site takeover.

🟠

Likely Case

Extraction of sensitive booking data, user information, and potentially WordPress authentication credentials.

🟢

If Mitigated

Limited information disclosure if database permissions are properly restricted and sensitive data is encrypted.

🌐 Internet-Facing: HIGH - The vulnerability is exploitable by unauthenticated attackers and affects internet-facing WordPress sites.

🏢 Internal Only: MEDIUM - Internal systems are still vulnerable but have reduced attack surface compared to internet-facing systems.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires obtaining a valid public_token and crafting SQL injection payloads in JSON format.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 1.6.9.28 or later

Vendor Advisory: https://wordpress.org/plugins/simply-schedule-appointments/#developers

Restart Required: No

Instructions:

1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find 'Simply Schedule Appointments'. 4. Click 'Update Now' if available. 5. Alternatively, download latest version from WordPress plugin repository and manually update.

🔧 Temporary Workarounds

Disable vulnerable endpoints

all

Temporarily block access to the vulnerable API endpoints via web application firewall or .htaccess rules

# Add to .htaccess to block specific endpoints
RewriteEngine On
RewriteCond %{REQUEST_URI} ^/wp-json/ssa/v1/ [NC]
RewriteRule ^ - [F,L]

🧯 If You Can't Patch

Implement a web application firewall (WAF) with SQL injection protection rules
Restrict access to the booking functionality or disable the plugin entirely

🔍 How to Verify

Check if Vulnerable:

Check WordPress admin panel → Plugins → Simply Schedule Appointments → check version number

Check Version:

wp plugin list --name='simply-schedule-appointments' --field=version

Verify Fix Applied:

Verify plugin version is 1.6.9.28 or higher in WordPress admin panel

📡 Detection & Monitoring

Log Indicators:

Unusual POST requests to /wp-json/ssa/v1/ endpoints with JSON payloads
SQL error messages in WordPress debug logs
Multiple failed booking attempts with malformed data

Network Indicators:

HTTP POST requests containing 'append_where_sql' parameter in JSON bodies
Unusual database query patterns from WordPress application

SIEM Query:

source="web_logs" AND (uri_path="/wp-json/ssa/v1/*" AND request_body LIKE "%append_where_sql%")

📊 Metadata

CVE ID: CVE-2026-1708

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CWE: CWE-89

Published: March 11, 2026

Last Updated: March 11, 2026

🔗 References

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