HTTP Request Smuggling Affecting org.springframework:spring-webflux package, versions [5.3.0,6.0.0)[6.1.0-M1,6.2.19)[7.0.0-M1,7.0.8)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JAVA-ORGSPRINGFRAMEWORK-18326608
- published27 Jul 2026
- disclosed8 Jun 2026
- creditYuki Matsuhashi
Introduced: 8 Jun 2026
CVE-2026-41853 (opens in a new tab)How to fix?
Upgrade org.springframework:spring-webflux to version 6.0.0, 6.2.19, 7.0.8 or higher.
Overview
org.springframework:spring-webflux is a Spring Framework module that contains support for reactive HTTP and WebSocket clients as well as for reactive server web applications including REST, HTML browser, and WebSocket style interactions.
Affected versions of this package are vulnerable to HTTP Request Smuggling. via multipart request parsing discrepancies between Spring MVC/WebFlux and intermediary security devices. An attacker can bypass Web Application Firewall (WAF) or proxy security controls by sending crafted multipart requests that are interpreted differently by the intermediary and the Spring application, allowing malicious content to evade inspection and reach the backend application.