CVE-2026-93659 in Community Store
Summary
by MITRE • 09/18/2026
Concrete CMS Community Store before 2.7.8 renders customer-supplied order fields without HTML escaping in checkout and admin views. Unauthenticated attackers can store script payloads in billing name, email, or phone fields that execute in authenticated manager sessions to create rogue accounts or exfiltrate data.
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified in Concrete CMS Community Store prior to version 2.7.8 represents a critical Cross-Site Scripting (XSS) flaw rooted in the improper handling of user-supplied input during order processing workflows. Specifically, the application fails to apply HTML entity encoding or other appropriate sanitization techniques when rendering customer-provided data within both public-facing checkout pages and internal administrative interfaces. This lack of output escaping allows malicious actors to inject executable JavaScript code directly into the DOM structure through standard form fields such as billing name, email address, and phone number during the order placement process. The core technical failure lies in the assumption that input validation alone is sufficient for security, neglecting the fundamental principle of defense-in-depth which requires strict output encoding regardless of prior sanitization efforts.
From an operational perspective, this vulnerability enables unauthenticated attackers to achieve persistent code execution within the context of authenticated sessions belonging to store administrators or managers. Because the malicious script payloads are stored in the database alongside legitimate order data, they persist until manually removed by site operators. When a manager logs into the administrative dashboard and views pending orders or customer details, the browser interprets the injected JavaScript as part of the page content rather than static text. This context switch from unauthenticated user input to authenticated administrator view creates a powerful attack vector that bypasses standard authentication controls entirely. The attacker does not need valid credentials; they only need to submit an order with maliciously crafted fields, effectively poisoning the data source for all subsequent viewers.
The impact of this vulnerability extends beyond simple defacement or session hijacking in many scenarios due to the elevated privileges associated with administrative views. Attackers can leverage the stored script payload to perform actions on behalf of the authenticated manager, such as creating new administrator accounts to establish persistent backdoor access, modifying product configurations, or exfiltrating sensitive customer data including payment information and personal identifiable information via external beacon requests. This capability transforms a simple input validation error into a severe compromise of system integrity and confidentiality. The ability to execute arbitrary code in the admin context effectively grants full control over the e-commerce platform, allowing for complete takeover of the business operations hosted on Concrete CMS.
This flaw is categorized under CWE-79 Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting within industry standard classification systems. In terms of tactical mapping to the MITRE ATT&CK framework, this vulnerability facilitates initial access and privilege escalation through stored XSS techniques that target administrative interfaces. The attack chain typically involves data injection during normal operation followed by execution upon privileged context rendering, aligning with tactics related to client-side exploitation and credential harvesting. Remediation requires immediate upgrading to version 2.7.8 or later where the output encoding mechanisms have been corrected for all relevant fields in both checkout and admin templates. Additionally, implementing Content Security Policy headers can provide an additional layer of mitigation by restricting script execution sources while longer-term architectural improvements focus on adopting strict context-aware escaping libraries across the entire application stack to prevent similar input-output mismatches in future development cycles.