Session Fixation 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-18326552
- published27 Jul 2026
- disclosed8 Jun 2026
- creditUnknown
Introduced: 8 Jun 2026
CVE-2026-41839 (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 Session Fixation. via session fixation handling. An attacker controlling a compromised subdomain can obtain a known session identifier and subsequently cause it to be associated with an authenticated user session, allowing unauthorized use of the victim's authenticated session.
Note: This is only exploitable if an attacker can control or execute script within a subdomain of the target application (for example through a cross-site scripting vulnerability).