CVE-2026-27417: Sweet Date Object Injection Vulnerability

CVE-2026-27417 Overview

A deserialization of untrusted data vulnerability has been identified in the SeventhQueen Sweet Date WordPress theme (sweetdate) that allows PHP Object Injection attacks. This vulnerability affects Sweet Date theme versions prior to 4.0.1 and is classified under CWE-502 (Deserialization of Untrusted Data).

Critical Impact

Attackers can exploit this PHP Object Injection vulnerability to execute arbitrary code, manipulate application logic, or achieve remote code execution depending on the gadget chains available in the WordPress installation.

Affected Products

• SeventhQueen Sweet Date WordPress theme versions prior to 4.0.1
• WordPress installations utilizing the vulnerable Sweet Date theme
• Websites with active Sweet Date theme installations

Discovery Timeline

• 2026-03-05 - CVE CVE-2026-27417 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-27417

Vulnerability Analysis

This vulnerability involves improper handling of serialized data within the Sweet Date WordPress theme. When user-controlled input is passed to PHP's unserialize() function without proper validation, attackers can inject malicious serialized objects. Upon deserialization, these objects can trigger dangerous "magic methods" such as __wakeup(), __destruct(), or __toString() that may be present in the application or its dependencies.

The exploitation potential depends heavily on the presence of "gadget chains" - sequences of classes and methods that can be chained together to achieve malicious outcomes. In WordPress environments, multiple plugins and themes often provide exploitable gadget chains that can lead to file operations, database manipulation, or remote code execution.

Root Cause

The root cause of this vulnerability is the unsafe deserialization of user-supplied input without proper validation or sanitization. The Sweet Date theme processes serialized data from untrusted sources, allowing attackers to craft malicious serialized payloads that instantiate arbitrary PHP objects. This violates the security principle of never trusting user input, particularly when that input controls object instantiation.

Attack Vector

The attack vector involves submitting specially crafted serialized PHP objects through user-controllable input fields that are subsequently deserialized by the vulnerable theme. An attacker would typically identify an entry point where serialized data is accepted, craft a malicious payload containing objects with dangerous magic methods, and submit this payload to trigger the vulnerability during deserialization.

The exploitation requires the attacker to have knowledge of available PHP classes within the WordPress installation that contain exploitable magic methods. Successful exploitation can result in arbitrary file read/write operations, SQL injection through object properties, denial of service, or in severe cases, remote code execution when combined with appropriate gadget chains.

Detection Methods for CVE-2026-27417

Indicators of Compromise

• Unusual serialized PHP data patterns in HTTP request parameters, cookies, or POST data containing O: object notation
• Web server logs showing requests with base64-encoded or URL-encoded serialized payloads targeting theme endpoints
• Unexpected file system changes or new files created in WordPress directories
• Database modifications not attributable to legitimate administrative actions
• PHP error logs indicating class instantiation failures or magic method exceptions

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block requests containing PHP serialized object patterns
• Monitor for suspicious patterns such as O:[0-9]+: in incoming request data which indicate serialized PHP objects
• Deploy runtime application self-protection (RASP) solutions that can detect deserialization attacks
• Audit web server access logs for unusual request patterns targeting Sweet Date theme files

Monitoring Recommendations

• Enable verbose PHP error logging to capture deserialization-related exceptions and warnings
• Implement file integrity monitoring on WordPress core files, theme directories, and plugin directories
• Monitor outbound network connections from the web server for potential data exfiltration
• Set up alerts for new user account creation or privilege escalation events in WordPress

How to Mitigate CVE-2026-27417

Immediate Actions Required

• Update the Sweet Date theme to version 4.0.1 or later immediately
• Audit WordPress installations to identify all sites using vulnerable Sweet Date theme versions
• Review recent server logs for any indicators of exploitation attempts
• Consider temporarily disabling or switching themes if immediate patching is not possible
• Implement WAF rules to block serialized PHP object patterns as an interim measure

Patch Information

The vulnerability has been addressed in Sweet Date theme version 4.0.1. Website administrators should update to this version or later through the WordPress theme update mechanism or by obtaining the patched version from the theme vendor. For detailed vulnerability information, refer to the Patchstack SweetDate Theme Vulnerability advisory.

Workarounds

• Deploy a Web Application Firewall with rules to filter serialized PHP object patterns in requests
• Implement input validation at the web server level using ModSecurity or similar technologies to reject requests containing serialized data patterns
• If the theme is not actively required, consider deactivating the Sweet Date theme until the patch can be applied
• Restrict access to WordPress admin and theme-related endpoints using IP allowlisting where feasible
• Ensure PHP is configured with open_basedir restrictions to limit potential damage from file operations