CVE-2026-22735 is a vulnerability identified in the Spring Foundation framework, specifically affecting Spring MVC and WebFlux applications that utilize Server-Sent Events (SSE). The issue manifests as stream corruption during SSE communication, potentially leading to data integrity issues within the event stream. Affected versions span multiple major releases: 5.3.0 through 5.3.46, 6.1.0 through 6.1.25, 6.2.0 through 6.2.16, and 7.0.0 through 7.0.5. The vulnerability arises from improper handling of SSE streams, which can cause corrupted or malformed event data to be delivered to clients. The CVSS v3.1 base score is 2.6, reflecting a low severity due to the requirement for network access, low privileges, user interaction, and high attack complexity. The impact is limited to integrity, with no confidentiality or availability effects reported. No known exploits have been observed in the wild, and no patches or mitigations have been explicitly linked in the provided data. This vulnerability highlights the need for careful handling of SSE in Spring applications to avoid data corruption issues that could affect application behavior or client-side processing.

The primary impact of CVE-2026-22735 is on the integrity of data streams in applications using Spring MVC or WebFlux with SSE. Corrupted event streams could lead to incorrect or incomplete data being processed by clients, potentially causing application logic errors, inconsistent user experiences, or downstream processing faults. While the vulnerability does not affect confidentiality or availability, integrity issues in real-time event streams could disrupt critical business processes relying on accurate event delivery, such as financial transactions, monitoring dashboards, or notification systems. The requirement for user interaction and low privileges reduces the likelihood of widespread exploitation, and the high attack complexity further limits the risk. However, organizations with high-dependency on SSE for real-time data delivery should consider the risk carefully, especially in environments where data integrity is paramount.

Organizations should proactively monitor for updates from the Spring Foundation project and apply patches promptly once they become available for the affected versions. Until patches are released, developers should review their use of Server-Sent Events in Spring MVC and WebFlux applications to identify potential misuse or improper stream handling that could lead to corruption. Implementing additional validation and error handling on both server and client sides can help detect and mitigate corrupted event streams. Limiting exposure of SSE endpoints through network segmentation, access controls, and authentication can reduce the attack surface. Additionally, educating developers on secure SSE implementation best practices and conducting thorough testing of SSE functionality under various conditions can prevent exploitation. Monitoring application logs for anomalies in SSE traffic may also provide early detection of attempted exploitation.