CVE-2026-113808 in Network Security
Summary
by MITRE • 10/20/2026
A Stored Cross-Site Scripting vulnerability exists in the SNS enrollment Portal.
Through the captive portal an attacker can inject an XSS when requesting user creation. The stored XSS can only be triggered during validation by the administrator.
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Analysis
by VulDB Data Team • 10/20/2026
The identified security flaw represents a classic instance of Stored Cross-Site Scripting, commonly categorized under CWE-79 in the Common Weakness Enumeration framework. This vulnerability resides within the SNS enrollment portal and specifically targets the user creation workflow accessible through the captive portal interface. The core technical deficiency lies in the insufficient sanitization or validation of input data provided during the registration process. When an attacker submits a malicious payload disguised as legitimate user information, such as a username or email address, the application fails to properly encode special characters before storing this data in its backend database. Consequently, the malicious script is persisted on the server side rather than being executed immediately within the context of the request that created it.
The operational impact of this vulnerability is distinct from reflected XSS attacks because the payload remains dormant until a specific trigger event occurs. In this scenario, the stored XSS is not triggered by general user activity but specifically during the administrative validation phase. This means that when an administrator logs into the portal to review and approve new user registrations, their browser renders the page containing the malicious script embedded within the pending user data. Because the administrator typically possesses elevated privileges or access to sensitive management interfaces, executing arbitrary JavaScript in their session context can lead to severe consequences. The attacker gains the ability to execute scripts with the same trust level as the application, potentially allowing for session hijacking, credential theft via keyloggers, or unauthorized administrative actions performed under the guise of the administrator account.
From a threat modeling perspective aligned with the MITRE ATT&CK framework, this vulnerability facilitates techniques associated with Collection and Credential Access, specifically targeting browser-based capture such as Keylogging (T1056) or Session Cookie Stealing (T1539). The attacker leverages the trusted relationship between the administrator's session and the application to bypass authentication controls indirectly. Since the payload is stored, it does not require complex social engineering to trick a random user into clicking a link; instead, it relies on the routine operational procedure of an authorized individual reviewing new entries. This persistence mechanism ensures that every time an admin validates a compromised entry, their security posture is undermined without any additional effort from the attacker after the initial injection.
Mitigation strategies must address both immediate remediation and long-term architectural improvements. The primary technical fix involves implementing strict output encoding for all data rendered in HTML contexts, ensuring that special characters like angle brackets, ampersands, and quotes are converted to their corresponding HTML entities before display. Additionally, input validation should be enforced on the server side using a whitelist approach, rejecting any user-supplied data containing unexpected or dangerous patterns rather than attempting to sanitize them after the fact. Deploying Content Security Policy headers can also serve as an effective defense-in-depth measure by restricting the sources from which scripts are allowed to execute, thereby neutralizing many XSS payloads even if they manage to bypass input filters. Regular security code reviews and automated static application security testing should be integrated into the development lifecycle to detect such injection flaws early in the software development process.