Spring MVC WebFlux Server-Sent Events Stream Corruption

CVE-2026-47890 represents a critical vulnerability affecting Spring Framework versions 7.0.0-7.0.8 and 6.2.0-6.2.19 when Server-Sent Events (SSE) are combined with view fragments in Spring MVC and WebFlux applications. The vulnerability allows attackers to corrupt SSE streams, potentially leading to data integrity violations, denial of service conditions, or manipulation of real-time communications. This impacts any organization using affected Spring Framework versions to deliver real-time data via SSE—including financial institutions, collaboration platforms, notification systems, and IoT dashboards. The critical CVSS score of 9.8 underscores the severity, as stream corruption in production environments can cascade into application instability, user session hijacking, or exposure of sensitive streamed data.

While this CVE currently maps to zero Casky skills with direct MITRE ATT&CK alignment, practitioners leveraging Casky.ai's Claude-powered analysis would detect attack indicators through behavioral pattern recognition focused on stream manipulation and protocol anomalies. Extended reasoning capabilities would identify suspicious SSE frame sequences, malformed fragment responses, and unexpected stream terminations that precede or accompany exploitation attempts. Security teams would observe findings flagging abnormal SSE handshakes, fragment injection patterns, and stream desynchronization events—indicators that presage CWE-93 protocol violations. As additional skills are mapped to reflect SSE exploitation techniques and stream manipulation vectors, practitioners can expect enhanced detection coverage across impact assessment (data exfiltration via corrupted streams) and lateral movement scenarios where compromised SSE channels facilitate command injection or credential harvesting.