[HIGH] CVE-2026-6455 — CVSS 8.1 (May 28, 2026)

A HIGH-severity vulnerability identified as CVE-2026-6455 has been published on May 28, 2026 with a CVSS base score of 8.1. This security advisory provides a detailed breakdown of the vulnerability, its potential impact, weakness classification, and actionable steps to protect your systems.

Vulnerability Details

CVE ID: CVE-2026-6455
Severity: HIGH
CVSS Score: 8.1
Published: May 28, 2026
Weakness (CWE): CWE-352

Technical Description

The WP Contact Form 7 DB Handler plugin for WordPress is vulnerable to Cross-Site Request Forgery leading to Arbitrary File Deletion via SQL Injection and PHP Object Injection in versions up to and including 3.0. This is due to a missing nonce verification in the process_bulk_action() function, the nonce check is only executed when _wpnonce is present in the POST body, allowing it to be trivially bypassed by omitting the field, combined with the use of an unsanitized, unparameterized user-supplied value in a numeric SQL context (WHERE ID = $ID) and the unsafe deserialization of the query result's post_content field. An attacker can craft a CSRF page that tricks a logged-in administrator into triggering a UNION-based SQL injection payload (using CHAR() to avoid esc_sql quote-escaping) that returns a malicious serialized PHP array as post_content; upon deserialization, array values associated with keys containing 'ys_cfdbh_file' are used as file paths appended to the uploads directory path without any path traversal validation, and then passed to wp_delete_file(), allowing the attacker to delete arbitrary files on the server (e.g., wp-config.php, system files).

Potential Impact

If exploited, this high-severity vulnerability could allow an attacker to tamper with system integrity, cause a denial of service. Organizations running affected software should treat this as a priority remediation item.

Recommended Action

No official patch is available yet. Until one is released:

1. Monitor the official NVD page and vendor channels for patch announcements.
2. Restrict access to the affected system or service where possible.
3. Apply network-level mitigations such as firewall rules or WAF policies.
4. Enable logging and alerting for anomalous activity related to this vulnerability.
5. Review your incident response plan in case of active exploitation.

View full details on NVD →

References

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