CVE-2026-59281 in Spring Framework
Summary
by MITRE • 08/27/2026
Spring MVC and WebFlux applications that obtain a data-binding Errors instance with HTML escaping enabled and then render field errors using the no-argument Errors.getFieldErrors() or Errors.getFieldError() accessors are vulnerable to arbitrary HTML/JavaScript code injection, potentially resulting in a reflected cross-site scripting (XSS) vulnerability. Spring Framework 7.0.0 - 7.0.8 Spring Framework 6.2.0 - 6.2.19 Spring Framework 6.1.0 - 6.1.28 Spring Framework 6.0.0 - 6.0.30 Spring Framework 5.3.0 - 5.3.49 Spring Framework 5.2.25.RELEASE and earlier
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Analysis
by VulDB Data Team • 08/27/2026
The vulnerability described involves a critical flaw in the data binding error handling mechanisms of the Spring MVC and WebFlux frameworks, specifically affecting versions ranging from Spring Framework 5.2.25.RELEASE through to version 7.0.8. This issue arises when an application developer retrieves an Errors instance that has HTML escaping enabled for field errors but subsequently renders those errors using specific accessor methods without proper context or additional sanitization. The core technical flaw lies in the behavior of the no-argument getFieldErrors() and getFieldError() accessors, which return raw error messages including any user-supplied input that was bound to form fields. When these frameworks are configured with HTML escaping enabled for general data binding, it is often assumed that all output will be safely escaped. However, this assumption fails when developers explicitly call these specific methods to retrieve and render field errors in views or API responses, as the framework does not automatically apply encoding to the strings returned by these accessors if they are passed directly to rendering contexts that interpret HTML content.
This architectural oversight creates a pathway for reflected cross-site scripting attacks. An attacker can craft malicious input containing arbitrary HTML tags or JavaScript code and submit it through any form field bound within the vulnerable Spring application. Because the data binding process captures this input as part of the error message when validation fails, the raw payload is stored in the Errors object. When the application subsequently renders the page to display these errors back to the user, the no-argument accessor methods return the unescaped malicious string. If the view technology or response writer interprets this output as HTML rather than plain text, the browser executes the embedded script code within the context of the victim's session. This results in a reflected XSS vulnerability where the attack payload is not stored on the server but is immediately executed upon rendering the error page to the targeted user.
The operational impact of this vulnerability extends beyond simple script execution. Reflected cross-site scripting can be leveraged by attackers to steal sensitive information such as session cookies, authentication tokens, or personally identifiable data displayed within the application interface. Furthermore, it enables account takeover scenarios if combined with other vulnerabilities like CSRF, allowing an attacker to perform actions on behalf of a legitimate user without their knowledge. In enterprise environments where Spring MVC and WebFlux are heavily utilized for building web applications, this flaw represents a significant risk vector because many legacy or convention-driven codebases may rely on default error rendering behaviors that inadvertently expose these raw strings. The scope is particularly wide given the extensive range of affected versions, impacting both older maintenance releases like 5.3.x and newer major releases up to 7.0.8, indicating a systemic design issue in how field errors are exposed to view layers across multiple generations of the framework.
From a classification perspective, this vulnerability aligns with CWE-79: Improper Neutralization of Input During Web Page Generation, commonly known as Cross-site Scripting (XSS). Specifically, it falls under the subcategory of reflected XSS where user input is echoed back in an error message without adequate sanitization before being rendered by the client-side browser. In terms of offensive security tactics, this aligns with MITRE ATT&CK technique T1059: Command and Control via Application Layer Protocol or more specifically T1189: Drive-by Client Side Scripting if leveraged through phishing links that trigger validation errors on vulnerable forms. The attack vector is typically web-based, requiring the victim to interact with a maliciously crafted form submission that triggers server-side validation failure, thereby causing the application to return the injected script within its HTTP response body.
Mitigation strategies must address both immediate remediation and long-term architectural improvements. For applications currently running on affected versions, upgrading to Spring Framework 7.0.9 or later is the primary recommendation as these releases include fixes for this specific data binding behavior. If an upgrade is not immediately feasible, developers should avoid using the no-argument getFieldErrors() or getFieldError() methods directly in view templates when HTML output is expected. Instead, they should utilize accessor methods that allow specifying a default value or explicitly apply encoding functions provided by the template engine to ensure any special characters are escaped before rendering. Additionally, implementing strict Content Security Policy headers can help mitigate the impact of successful XSS attempts by restricting script execution sources. Regular security code reviews focusing on how error messages and user input are rendered in view layers are essential to prevent similar oversights in future development cycles.