ConvertPlus - Security Vulnerability (CVE-2026-87741)
CVE-2026-87741
The ConvertPlus plugin for WordPress is vulnerable to Deserialization of Untrusted Data in all versions up to, and including, 3.6.3 via the style parameter of the cp_display_preview_modal AJAX action. The vulnerability exists because the action's nonce guard is gated behind an isset() check and fails open when the cp_admin_page_nonce parameter is omitted entirely, no capability check is performed on the callback, and sanitize_text_field() — applied to the $style value before it is concatenated directly into a shortcode string evaluated by do_shortcode() — does not strip shortcode delimiters, allowing an attacker to inject a second, fully attacker-controlled [smile_modal] invocation that causes smile_modal_popup() to pass attacker-supplied base64-decoded bytes to maybe_unserialize() with no allowed_classes restriction. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject a PHP object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present.
CVE-2026-87741
HIGH
CVSS 8.8
Published 2026-09-28
Updated 2026-09-29
AI Risk High (86/100)
Active Exploit: No strong signal
Published Exploit: No public exploit references
Priority: P2 Urgent
Severity Band
HIGH
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected Components
1
Reference Links
2
AI Risk Engine
High (86/100)
Exploitability
High
Active Exploitation
No strong signal
Published Exploit Status
No public exploit references
AI Context
Machine-generated threat intelligence
AI
Updated just now
AI enriched just now (2026-10-01 19:55 UTC)
Technical Summary
The ConvertPlus plugin for WordPress is vulnerable to Deserialization of Untrusted Data in all versions up to, and including, 3.6.3 via the style parameter of the cp_display_preview_modal AJAX action. The vulnerability exists because the action's nonce guard is gated behind an isset() check and fails open when the cp_admin_page_nonce parameter is omitted entirely, no capability check is performed on the callback, and sanitize_text_field() — applied to the $style value before it is concatenated directly into a shortcode string evaluated by…
Potential Impact
Severity is HIGH (CVSS 8.8). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.
Exploitability Assessment
Exploitability is assessed as High based on remote code execution potential.
Primary risk drivers: remote code execution potential
Mitigation Recommendations
Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.
Detection & Monitoring
Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.
Business Impact Lens
AI risk score 86/100 (High, High) with priority P2 Urgent. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.
