CVE-2026-47893 in Spring
Summary
by MITRE • 08/27/2026
A Spring WebFlux application that supports WebSocket connections may expose indirectly sensitive user information by including request headers in an exception reason. 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 identified in the specified versions of the Spring Framework, particularly affecting applications utilizing Spring WebFlux with WebSocket support, represents a significant information disclosure risk rooted in improper exception handling mechanisms. When an application encounters an error during the processing of a WebSocket connection or related HTTP request, the framework may inadvertently include sensitive data from the original client request within the details of the thrown exception. This behavior is not limited to direct exposure through standard API responses but occurs indirectly when these exceptions are logged, reported to monitoring systems, or displayed in debug interfaces that are accessible to unauthorized parties. The core technical flaw lies in the default error handling logic which captures and propagates full request context, including headers, without sufficient sanitization or filtering for sensitive fields such as authentication tokens, session identifiers, or personally identifiable information contained within those headers.
This issue is categorized under CWE-209: Generation of Error Message Containing Sensitive Information, a classification that highlights the danger of leaking internal state or user data through error outputs intended for debugging rather than end-users. From an offensive security perspective, this vulnerability aligns with ATT&CK technique T1530: Data from Cloud Storage Object Discovery and potentially T1078: Valid Accounts if the exposed headers reveal authentication credentials that can be replayed by attackers. The operational impact is severe because WebSocket connections often maintain long-lived sessions where sensitive data exchange occurs continuously. An attacker who gains access to server logs, error reporting services like Sentry or Datadog, or even local file systems on compromised servers could extract these leaked headers. This information can facilitate further attacks such as session hijacking, privilege escalation, or targeted phishing campaigns by revealing the internal structure of user interactions and authentication mechanisms.
The affected versions span a wide range of Spring Framework releases from 5.2.25.RELEASE through to 7.0.8, indicating that this is a systemic issue in how WebFlux handles WebSocket-related exceptions across multiple major release lines. Applications relying on these frameworks for reactive web services are at risk if they do not implement custom error handling strategies that explicitly strip or mask sensitive header data before it enters the exception chain. The persistence of this vulnerability in such widely used enterprise software underscores the importance of rigorous code review practices and automated static analysis tools configured to detect potential information leaks in error paths.
Mitigation requires a multi-layered approach starting with upgrading to patched versions of the Spring Framework where available, as newer releases typically include fixes that sanitize exception messages or restrict access to sensitive request attributes during error processing. For environments unable to upgrade immediately, developers must implement custom ErrorWebExceptionHandler beans that intercept exceptions and ensure that no raw request headers are included in log statements or response bodies. This involves explicitly filtering out known sensitive header names such as Authorization, Cookie, X-Auth-Token, and any other proprietary identifiers before they can be serialized into error messages. Additionally, organizations should review their logging configurations to prevent the automatic inclusion of exception stack traces containing these details in production environments, adhering to the principle of least privilege for log visibility. Regular security audits focusing on error handling paths are essential to ensure that no residual sensitive data remains exposed through indirect channels like monitoring dashboards or third-party analytics platforms integrated with the application infrastructure.