CVE-2026-5699 in Sabbatic
Summary
by MITRE • 10/29/2026
Stored Cross-Site Scripting (XSS) vulnerability in SABBATIC application that allows an attacker to store JavaScript code so that when a user views the page, code can be executed in the victim's browser. The list of assigned parameters and identifiers is as follows: parameter 'companyName' in /empresa endpoint;
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 10/29/2026
The identified vulnerability represents a classic Stored Cross-Site Scripting flaw within the SABBATIC application, specifically targeting the companyName parameter at the /empresa endpoint. This type of vulnerability arises when an application accepts user-supplied input and stores it for later use without performing adequate validation or sanitization against script injection attacks. In this specific instance, the lack of proper encoding or filtering allows an attacker to inject malicious JavaScript code into the database via the company name field. Unlike reflected XSS where the payload is executed immediately from a crafted link, stored XSS persists on the server side, meaning that every user who subsequently views the affected page will have their browser execute the injected script automatically. This persistence transforms the vulnerability from a transient issue into a persistent threat vector capable of affecting multiple victims over an extended period without further interaction from the attacker after the initial injection.
From a technical perspective, the core failure lies in the application's handling of untrusted data at both input and output stages. The backend likely stores the raw string provided by the user for the companyName field directly into the database structure associated with the /empresa endpoint. When this data is retrieved and rendered within an HTML context on the client side, the browser interprets the embedded JavaScript as executable code rather than static text content. This behavior violates fundamental web security principles regarding the separation of code and data. The absence of Context-Aware Output Encoding ensures that special characters such as angle brackets, quotes, and ampersands are not converted into their corresponding HTML entities before rendering. Consequently, any script tags or event handlers embedded within the company name string bypass the browser's same-origin policy restrictions relative to the application domain, allowing the attacker to run arbitrary code with the privileges of a legitimate user logged into the SABBATIC platform.
The operational impact of this vulnerability is severe and multifaceted, primarily centering on session hijacking and data exfiltration. An attacker can craft a payload that steals authentication cookies or tokens associated with the victim's active session. By transmitting these credentials to an external server controlled by the adversary, the attacker gains unauthorized access to the victim's account without needing their password. Beyond credential theft, this vulnerability enables broader attacks such as keylogging, where malicious scripts monitor keystrokes to capture sensitive information like passwords and credit card numbers entered on subsequent pages within the application. Additionally, attackers can manipulate the DOM of the page to display fake login forms or redirect users to phishing sites designed to harvest credentials from unsuspecting employees or administrators. The trust relationship between the user's browser and the SABBATIC domain is exploited fully, allowing malicious actions to be performed as if they originated from a legitimate source within the application itself.
This vulnerability aligns with CWE-79, which categorizes improper neutralization of input during web page generation known as Cross-site Scripting. It also maps directly to MITRE ATT&CK technique T1059.007, specifically JavaScript execution under client-side scripting. The persistence mechanism classifies it further within the context of persistent threats where a single injection point can compromise numerous users over time. To mitigate this risk effectively, developers must implement strict input validation that rejects any non-alphanumeric characters in fields expected to contain only company names or similar identifiers. More critically, output encoding must be applied consistently across all views rendering user-supplied data. Utilizing modern web frameworks with built-in auto-escaping features can significantly reduce the likelihood of such errors. Furthermore, implementing a Content Security Policy header that restricts script execution sources adds an essential layer of defense in depth, ensuring that even if malicious scripts are injected into the DOM, they cannot execute unless explicitly allowed by policy rules. Regular security testing including automated static analysis and dynamic penetration testing should be integrated into the development lifecycle to detect such flaws before deployment.