[HIGH] CVE-2026-5809 — CVSS 7.1 (April 11, 2026)

A HIGH-severity vulnerability identified as CVE-2026-5809 has been published on April 11, 2026 with a CVSS base score of 7.1. 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-2026-5809
Severity: HIGH
CVSS Score: 7.1
Published: April 11, 2026
Weakness (CWE): CWE-73

Technical Description

The wpForo Forum plugin for WordPress is vulnerable to Arbitrary File Deletion in versions up to and including 3.0.2. This is due to a two-step logic flaw: the topic_add() and topic_edit() action handlers accept arbitrary user-supplied data[*] arrays from $_REQUEST and store them as postmeta without restricting which fields may contain array values. Because 'body' is included in the allowed topic fields list, an attacker can supply data[body][fileurl] with an arbitrary file path (e.g., wp-config.php or an absolute server path). This poisoned fileurl is persisted to the plugin's custom postmeta database table. Subsequently, when the attacker submits wpftcf_delete[]=body on a topic_edit request, the add_file() method retrieves the stored postmeta record, extracts the attacker-controlled fileurl, passes it through wpforo_fix_upload_dir() which only rewrites legitimate wpforo upload paths and returns all other paths unchanged, and then calls wp_delete_file() on the unvalidated path. This makes it possible for authenticated attackers, with subscriber-level access and above, to delete arbitrary files writable by the PHP process on the server, including critical files such as wp-config.

Potential Impact

If exploited, this high-severity vulnerability could allow an attacker to 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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