CVE-2025-26996 Overview
CVE-2025-26996 is a code injection vulnerability affecting the Fetch Designs Sign-up Sheets plugin for WordPress. The flaw allows attackers to inject arbitrary code through improperly controlled shortcode processing. According to the Patchstack Vulnerability Report, the issue affects all versions of sign-up-sheets up to and including 2.3.0.1. The vulnerability is categorized under [CWE-94] Improper Control of Generation of Code.
Critical Impact
Network-based attackers can inject code through shortcode processing without authentication, resulting in limited confidentiality and integrity impact on affected WordPress sites.
Affected Products
- Fetch Designs Sign-up Sheets plugin for WordPress
- All versions from n/a through 2.3.0.1
- WordPress installations with the sign-up-sheets plugin enabled
Discovery Timeline
- 2025-04-15 - CVE-2025-26996 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-26996
Vulnerability Analysis
The vulnerability resides in the Sign-up Sheets plugin's handling of shortcode input. The plugin fails to properly control the generation of code when processing user-supplied shortcode content. Attackers can craft malicious input that the plugin interprets as executable code rather than data.
The attack requires no authentication and no user interaction. The scope remains unchanged, and the vulnerability produces limited confidentiality and integrity impact without affecting availability. The EPSS probability sits in the lower percentile range, indicating limited observed exploitation activity at this time.
Root Cause
The root cause is improper input sanitization within the shortcode handler. The plugin passes untrusted input into a code evaluation or interpretation context without adequate validation. This class of flaw is common in WordPress plugins that dynamically evaluate shortcode attributes or content.
Attack Vector
An unauthenticated attacker sends a network request to a vulnerable WordPress site containing crafted shortcode content. When the plugin processes the input, the injected payload executes within the plugin's context. Refer to the Patchstack Vulnerability Report for further technical details on the shortcode injection mechanism.
Detection Methods for CVE-2025-26996
Indicators of Compromise
- Unexpected shortcode entries in WordPress posts, pages, or database tables associated with sign-up-sheets
- Anomalous outbound network connections originating from the web server hosting WordPress
- Modified plugin files or new files within the wp-content/plugins/sign-up-sheets/ directory
- Web server access logs showing repeated POST requests referencing sign-up sheet endpoints
Detection Strategies
- Inventory WordPress installations and identify sites running sign-up-sheets version 2.3.0.1 or earlier
- Review web application firewall logs for shortcode payloads containing PHP function names or evaluation constructs
- Correlate WordPress audit logs with process execution telemetry on the underlying host to identify code injection attempts
Monitoring Recommendations
- Enable file integrity monitoring on the WordPress wp-content/plugins/ directory
- Alert on new PHP processes spawned by the web server following shortcode-related HTTP requests
- Monitor for outbound connections from the WordPress host to previously unseen destinations
How to Mitigate CVE-2025-26996
Immediate Actions Required
- Identify all WordPress instances running the sign-up-sheets plugin and confirm the installed version
- Update the Sign-up Sheets plugin to a version released after 2.3.0.1 that addresses the shortcode injection issue
- If no patched version is available, deactivate and remove the plugin until a fix is released
- Review recent posts, pages, and database entries for suspicious shortcode content
Patch Information
Refer to the Patchstack Vulnerability Report for vendor patch status and remediation guidance. Administrators should apply the update through the WordPress plugin management console once available.
Workarounds
- Deactivate the sign-up-sheets plugin until a patched release is deployed
- Restrict access to WordPress endpoints that render sign-up shortcodes using web application firewall rules
- Limit the ability of unauthenticated users to submit content that reaches the vulnerable shortcode handler
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
