Summary

A SQL injection vulnerability (CVE-2026-0816) affecting the WordPress plugin “All push notification for WP” (versions up to and including 1.5.3) has been disclosed. The issue requires an authenticated user with Administrator privileges and exposes the site’s database to malicious SQL commands when the vulnerable delete_id parameter is used. The admin-only requirement reduces attack surface, but the consequences can be severe: data exfiltration, data modification, privilege escalation via database manipulation, or destructive activity. This advisory gives clear, actionable guidance to assess risk, detect attacks, and apply immediate and long-term mitigations.

Background and quick facts

• Affected plugin: All push notification for WP
• Vulnerable versions: ≤ 1.5.3
• Vulnerability type: SQL Injection (OWASP A03 / Injection)
• CVE: CVE-2026-0816
• Required privilege: Administrator (authenticated)
• CVSS (reported context): 7.6 (high)
• Published: 3 Feb, 2026

Important context: the vulnerability requires an attacker to operate with Administrator privileges. Remote unauthenticated attackers cannot exploit this directly unless they first obtain admin credentials or otherwise act as an administrator (compromised admin account, chained vulnerabilities, etc.). However, SQL injection grants direct database control and can cause severe damage even from an admin account.

How this vulnerability works (high level)

SQL injection occurs when user input is incorporated into a database query without proper sanitization or parameterization. In this case the plugin exposes a parameter named delete_id used in a database delete operation. If the plugin concatenates the delete_id value directly into SQL (for example: WHERE id = $delete_id) without prepared statements or validated integer conversion, an authenticated administrator can craft input that changes the SQL statement’s meaning.

Typical unsafe patterns (for illustration only — do not use in production):

• String concatenation into SQL like: $sql = "DELETE FROM {$table} WHERE id = " . $_REQUEST['delete_id'];
• Lack of input validation (not forcing numeric-only values for IDs)
• Lack of prepared statements ($wpdb->prepare) when using the WordPress database API
• Not verifying nonces or user capabilities before performing destructive operations

Because the vulnerability modifies or deletes database rows directly, successful exploitation can:

• Reveal sensitive data by altering queries
• Delete or modify user accounts, including elevating privileges
• Corrupt site content or configuration
• Insert backdoors or malicious data into the database

Likely impact and real-world risk

• Privilege requirement: Administrator — this limits potential attackers, but admin accounts are often targeted and can be compromised via credential reuse, phishing, weak passwords, or chained vulnerabilities.
• Attack complexity: Low for an authenticated admin. If an attacker can log in as admin, exploiting a delete_id SQL injection is straightforward when input is concatenated into queries.
• Impact severity: High. SQL injection can lead to complete compromise of site data (user records, API keys, order data), site defacement, persistent backdoors, or denial of service.
• Operational risk: On multi-admin sites (agencies, teams, client sites), a single compromised admin can pivot to full database-level damage.

Immediate steps for site administrators (what to do now)

If your site uses the affected plugin, apply these prioritized actions immediately.

1. Audit administrator accounts
   • Check Users → All Users and verify the list of administrators.
   • Force password resets for all administrator accounts.
   • Enable two-factor authentication (2FA) for every admin account.
   • Remove unused or suspicious administrator accounts.
   • Review role assignments and remove elevated roles where inappropriate.
2. Restrict plugin access
   • If the plugin has an admin UI, restrict access to its pages via IP allow-listing at the web server or reverse-proxy level where feasible.
   • Consider temporarily disabling the plugin if it is not required for critical operations.
3. Harden authentication
   • Disable XML-RPC if not required, or enforce strict authentication.
   • Require strong, unique passwords and turn on reCAPTCHA or bot mitigation on login pages.
4. WAF and firewall mitigations
   • Apply targeted rules to block suspicious delete_id values at admin endpoints. See the “Recommended WAF rules” section below for patterns to adapt to your environment.
5. Scan and monitor
   • Run a full site malware and file-change scan.
   • Inspect recent database changes for suspicious deletions, new admin accounts, or unauthorized content.
   • Review access logs for POST/GET requests containing delete_id in query strings or request bodies.
6. Back up and isolate
   • Take a full backup (files + database) and store it offline before making further changes.
   • If you confirm compromise, take the site offline while you investigate and restore from a known-clean backup.
7. Apply updates (when available)
   • If a patched plugin version is released, test and apply it promptly.
   • Until a patch is available, rely on the mitigations above to reduce risk.

Recommended WAF rules and firewall mitigations

While waiting for an official plugin patch, implement targeted firewall/WAF rules to reduce exploit attempts. Adapt these patterns to your platform and test thoroughly before enforcing blocking.

1. Allow only numeric values for ID parameters

   Rule: For admin endpoints that accept delete_id, only allow values matching ^\d+$. Challenge or block inputs containing quotes, SQL comment tokens (--, #), semicolons, or SQL keywords.

2. Block SQL keywords in admin requests

   Block requests to admin PHP scripts that include SQL keywords such as UNION SELECT, INFORMATION_SCHEMA, SLEEP(, or other obvious injection patterns in parameters.

3. Limit access to plugin admin pages by IP

   If administrators operate from fixed IP ranges, whitelist those IPs for plugin admin pages and block or challenge others.

4. Rate-limit admin actions

   Apply rate limits on admin POST requests. Excessive submissions from a single IP should trigger challenge or block actions.

5. Block inline SQL patterns

   Deny patterns such as \b(or|and)\b\s+1=1\b, ;--, /\*, \*/, @@, or hex-coded payloads in admin parameters.

6. Protect against CSRF and capability abuse

   Challenge or block requests that change data if they lack valid WordPress nonces. Enforce that destructive operations must be backed by capability checks.

7. Virtual patching

   If supported by your firewall, create a rule that blocks requests to the specific plugin endpoint when delete_id is present with unexpected content. Monitor before switching to blocking mode to avoid false positives.

Note: Test rules in monitor mode, validate expected admin workflows, and then switch to block mode when confident.

Developer guidance: how to fix the plugin code safely

If you are maintaining the plugin or responsible for custom code, apply these secure-coding steps to eliminate SQL injection by validating, sanitizing, and using parameterized queries.

1. Capability and nonce checks

   Verify the current user has the correct capability (for example current_user_can('manage_options')) and verify a WordPress nonce for the action (check_admin_referer or wp_verify_nonce).

2. Strong input validation

   Treat delete_id as an integer ID and cast/validate strictly:

   $delete_id = isset($_REQUEST['delete_id']) ? intval($_REQUEST['delete_id']) : 0;
   if ( $delete_id <= 0 ) {
       wp_die( 'Invalid ID' );
   }

3. Use prepared statements with $wpdb

   Avoid concatenating user input into SQL. Example safe deletion:

   global $wpdb;
   $table = $wpdb->prefix . 'your_table_name';
   
   $delete_id = isset($_REQUEST['delete_id']) ? intval( $_REQUEST['delete_id'] ) : 0;
   if ( $delete_id <= 0 ) {
       wp_die( 'Invalid ID' );
   }
   
   // Capability and nonce checks should be done before this
   $prepared = $wpdb->prepare( "DELETE FROM {$table} WHERE id = %d", $delete_id );
   $wpdb->query( $prepared );

4. Use WP API functions where possible

   If the data maps to posts or post meta, prefer wp_delete_post() or delete_post_meta() instead of raw SQL.

5. Log admin actions

   Record destructive operations with user, timestamp, and IP for audit and forensic investigation.

6. Sanitize outputs

   Escape HTML outputs and use wp_json_encode() for JSON responses.

7. Audit all endpoints

   Review all plugin endpoints and AJAX handlers for similar patterns. Fix any use of $wpdb concatenation, missing prepared statements, or absent nonce/capability checks.

8. Release a clear patch

   Ship a fixed plugin version with changelog and explicit guidance to users (rotate admin credentials, scan for compromise).

Detection: logs, queries and indicators of compromise (IoCs)

Search for these signals if you suspect attempts or successful exploitation.

1. Web server logs

   Look for requests containing delete_id= in GET or POST to admin-ajax.php, plugin admin pages, or other admin scripts.

   Example grep:

   grep -i "delete_id=" /var/log/apache2/*access.log

   Watch for parameters containing quotes, SQL keywords, or semicolons.

2. WordPress audit logs

   If you run activity logging, search for unexpected admin actions at times that align with suspicious requests.

3. Database anomalies

   Check for missing rows, unexplained deletions in plugin-related tables, or new/modified admin users:

   SELECT user_login, user_email, user_registered, user_status
   FROM wp_users
   WHERE user_status != 0
   OR ID IN (
     SELECT user_id FROM wp_usermeta
     WHERE meta_key = 'wp_capabilities' AND meta_value LIKE '%administrator%'
   );

4. Suspicious SQL queries

   If query logging is enabled, search for queries containing UNION, INFORMATION_SCHEMA, or SLEEP( near admin activity.

5. File system indicators

   Look for new PHP files under wp-content/uploads, modified core files, or injected obfuscated PHP. Use a file integrity scanner.

6. Unusual outbound connections

   Monitor for unexpected outbound traffic that could indicate data exfiltration.

If you confirm any of the above, treat it as a high-severity incident and follow the recovery checklist below.

Recovery and remediation checklist after confirmed exploitation

If you find clear signs of exploitation, proceed carefully and preserve evidence.

1. Isolate the site
   • Take the site offline or display a maintenance page while investigating.
   • If hosted, consider freezing the instance to preserve forensic evidence.
2. Preserve evidence
   • Secure copies of logs, database dumps, and filesystem snapshots before making changes.
3. Restore from known-clean backup
   • Restore files and database from a backup taken before the compromise and verify integrity.
4. Replace credentials and secrets
   • Rotate all admin passwords, API keys, OAuth tokens, database credentials, and service account credentials. Update WordPress salts in wp-config.php.
5. Hard delete malicious artifacts
   • Remove backdoors, rogue admin accounts, and malicious files. Re-scan after removal.
6. Apply permanent fixes
   • Update the vulnerable plugin to a fixed version when available, or remove/replace it with a secure alternative.
7. Re-scan and monitor
   • Run full malware scans and schedule frequent checks for several weeks. Enable extended logging and monitor for recurrence.
8. Notification and compliance
   • If sensitive user data was exfiltrated, follow applicable breach-notification requirements and notify affected users if required.
9. Conduct a post-mortem
   • Identify root cause, close gaps, and update security processes to prevent recurrence.

Hardening and ongoing best practices for WordPress sites

• Principle of least privilege: Grant administrator rights only to those who need them.
• Multi-factor authentication: Require 2FA for all admin accounts.
• Regular updates and plugin hygiene: Keep core, plugins, and themes updated. Remove inactive or unnecessary plugins.
• Security monitoring and logging: Maintain activity logs, file integrity checks, and intrusion detection.
• Backups and recovery planning: Maintain off-site backups with versioning and keep at least one clean offline backup.
• Use a WAF and managed firewall rules: Where feasible, a WAF can virtually patch vulnerabilities and block exploit attempts.
• Regular code audits: Perform security code reviews for plugins and custom code. Look for unsafe $wpdb patterns, missing prepared statements, and absent nonce/capability checks.
• Limit admin dashboard access: Protect wp-admin and wp-login.php via IP allowlist, HTTP auth, or other controls when feasible.

Frequently asked questions (FAQ)

Q: Do I need to panic because the vulnerability requires Administrator access?

No — but act quickly. Admin-only vulnerabilities are less likely to be exploited by anonymous attackers, but admin accounts are commonly targeted. If your site has multiple admins or remote admin access, take immediate steps.

Q: Is removing the plugin the only safe option?

Removing the plugin is a safe short-term response if you do not need it. If you must keep it, deploy virtual patching via firewall rules, tighten admin account security, and monitor logs until a patch is available.

Q: Should I change database credentials?

If you confirm exploitation or suspect the attacker had the ability to access or manipulate the database, rotate DB credentials and update wp-config.php. Also change API keys and salts.

Q: Will a WAF prevent all attacks?

A well-configured WAF reduces exposure and can virtual-patch known issues, but it does not replace secure coding, patch management, or good account hygiene. Use layered defenses: WAF + strong authentication + least privilege + code fixes.

Final notes from a Hong Kong security expert

This SQL injection advisory underlines recurring failures: inconsistent capability checks and unsafe DB handling at admin endpoints. Even "admin-only" issues can be abused when credentials are compromised or when vulnerabilities are chained.

Prioritise immediate steps: review admin accounts, enable 2FA, apply targeted firewall/WAF mitigations, and audit plugin code for unsafe $wpdb usage. Plugin maintainers must enforce capability and nonce checks, validate input strictly, and use prepared statements everywhere.

If you need professional assistance for forensic analysis, log review, or mitigation, engage an experienced incident response provider. Preserve evidence, avoid making destructive changes until evidence is captured, and follow the remediation checklist above.

Stay vigilant. If you have specific questions about detection queries, rule patterns, or secure coding details, provide your environment details (WP version, hosting type, plugin paths) and I can advise further.