CVE-2025-26740 Overview
CVE-2025-26740 is a DOM-based Cross-Site Scripting (XSS) vulnerability in the burgersoftware SpaBiz WordPress theme. The flaw affects all versions up to and including 1.0.18. It stems from improper neutralization of user input during web page generation, allowing attackers to inject and execute arbitrary script in a victim's browser. The issue is classified under CWE-79.
Exploitation requires low-privileged authentication and user interaction, and the scope change indicates the payload can affect resources beyond the vulnerable component. Successful exploitation compromises confidentiality, integrity, and availability of the affected browser session.
Critical Impact
Authenticated attackers can execute arbitrary JavaScript in victim browsers, potentially leading to session hijacking, credential theft, and unauthorized actions on behalf of authenticated users.
Affected Products
- burgersoftware SpaBiz WordPress theme
- SpaBiz versions from initial release through 1.0.18
- WordPress sites deploying the vulnerable theme
Discovery Timeline
- 2025-04-15 - CVE-2025-26740 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-26740
Vulnerability Analysis
The vulnerability is a DOM-based XSS flaw in the SpaBiz theme's client-side code. DOM-based XSS occurs when JavaScript running in the browser reads attacker-controllable data from a source such as location.hash, location.search, or document.referrer, then writes that data into a dangerous sink like innerHTML, document.write, or eval without proper sanitization.
Because the payload executes entirely within the Document Object Model (DOM), the malicious script may never traverse the server, complicating server-side detection. The attacker crafts a URL containing script content, then persuades an authenticated user to visit it.
The scope-changed impact means script executing in the SpaBiz theme context can influence resources outside its immediate security boundary, such as parent frames or other origins sharing the site.
Root Cause
The root cause is missing or insufficient input sanitization in client-side JavaScript rendered by the SpaBiz theme. User-controlled data flows into an HTML rendering sink without encoding, allowing browser interpretation of injected markup as executable script.
Attack Vector
An attacker sends a crafted link to an authenticated SpaBiz site user. When the target clicks the link, embedded JavaScript executes in their browser under the site's origin. The attacker can then steal session cookies, perform actions as the victim, or pivot to administrative functionality if the target holds elevated privileges. See the Patchstack advisory for additional technical detail.
Detection Methods for CVE-2025-26740
Indicators of Compromise
- Unexpected outbound requests from browsers visiting SpaBiz-powered WordPress sites to attacker-controlled domains
- URLs containing script fragments, HTML entities, or encoded payloads in query strings or fragments referencing SpaBiz theme paths
- WordPress access logs showing repeated authenticated requests followed by anomalous admin-area activity
- Session cookies used from geolocations or user agents inconsistent with the legitimate user
Detection Strategies
- Deploy web application firewall (WAF) rules that flag URLs containing script tags, javascript: schemes, or event handler attributes targeting SpaBiz endpoints
- Enable browser Content Security Policy (CSP) violation reporting to surface inline script execution attempts
- Perform static and dynamic analysis of the theme's JavaScript to identify unsafe sinks reading from location or document properties
Monitoring Recommendations
- Monitor WordPress user activity logs for privilege changes, unexpected plugin installations, or content modifications following link clicks
- Correlate authenticated session activity with referrer headers to identify link-driven exploitation attempts
- Track outbound DNS queries from client endpoints to newly registered or low-reputation domains
How to Mitigate CVE-2025-26740
Immediate Actions Required
- Identify all WordPress installations running the burgersoftware SpaBiz theme at version 1.0.18 or earlier
- Restrict administrative access to the affected sites until a patched version is deployed
- Advise privileged users to avoid clicking untrusted links referencing SpaBiz site URLs
- Rotate session tokens and administrative credentials if compromise is suspected
Patch Information
No fixed version is documented in the enriched CVE data at the time of publication. Consult the Patchstack advisory and the burgersoftware vendor channels for release updates. Apply the vendor patch immediately once available.
Workarounds
- Deploy a strict Content Security Policy that disallows inline scripts and restricts script sources to trusted origins
- Configure WAF rules to block requests containing common XSS payload signatures targeting SpaBiz URLs
- Temporarily switch to an alternative WordPress theme if patching is not feasible
- Enforce short authenticated session lifetimes and require reauthentication for administrative actions
# Example Content Security Policy header for WordPress (nginx)
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'; report-uri /csp-report" always;
# Example ModSecurity rule to block script tags in query strings
SecRule ARGS "@rx (?i)<script|javascript:|onerror=|onload=" \
"id:1002740,phase:2,deny,status:403,msg:'Potential XSS targeting SpaBiz theme'"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.