# CVE-2026-41839: VMware Spring Framework session fixation in WebFlux

Source: https://junglewise.ai/threats/cve-2026-41839-vmware-spring-framework-session-fixation-in-webflux  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-09. Updated: 2026-07-30  
License: CC BY 4.0 with a link back

CVE-2026-41839 · Severity: medium · CVSS 4.2 · Published 2026-06-09

Spring Framework is a widely used software framework for building Java-based web applications. A vulnerability in its WebFlux component could allow an attacker who has compromised a subdomain (for example, through a separate web attack) to hijack the session of a legitimate authenticated user. This could lead to unauthorized access to user accounts and sensitive data within the application.

Technologies: [org.springframework:spring-webflux (Maven)](https://junglewise.ai/threats/technologies/org-springframework-spring-webflux), [VMware Spring Framework](https://junglewise.ai/threats/technologies/spring-framework). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven), [VMware](https://junglewise.ai/threats/vendors/vmware).

## Quick answers

**Is CVE-2026-41839 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-41839 being exploited in the wild.

**How severe is CVE-2026-41839?** Medium severity, with a CVSS score of 4.2, published 9 June 2026.

**Which products and versions are affected?** org.springframework:spring-webflux (Maven) ECOSYSTEM:introduced=7.0.0,fixed=7.0.8; VMware Spring Framework 7.0.0 through 7.0.7; 6.2.0 through 6.2.18; 6.1.0 through 6.1.27; 5.3.0 through 5.3.48.

**Is there a fix for CVE-2026-41839?** Yes. org.springframework:spring-webflux (Maven): upgrade to 7.0.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-41839 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-41839?** Check whether you run org.springframework:spring-webflux (Maven) or VMware Spring Framework at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- org.springframework:spring-webflux (Maven): upgrade to 7.0.8 or later

  ```sh
  # set org.springframework:spring-webflux to 7.0.8 in your pom.xml or build.gradle
  ```


## Technical details

A session fixation vulnerability (CWE-384) exists in Spring Framework's WebFlux module. The flaw allows an attacker who has control over a subdomain (e.g., via XSS) to perform a session escalation attack by exchanging a known session ID for the session ID of an authenticated user. This occurs because the application may establish or transition to an authenticated session without properly invalidating the pre-existing session identifier. Exploitation requires network access and user interaction, with high attack complexity due to the prerequisite of a compromised subdomain. Patches are available in versions 7.0.8 and 6.2.19.

## Affected products

- VMware Spring Framework 7.0.0 through 7.0.7; 6.2.0 through 6.2.18; 6.1.0 through 6.1.27; 5.3.0 through 5.3.48

## Identifiers

- CVE-2026-41839
- GHSA-4hfh-6x8g-gwpp

## Timeline

- 2026-06-09: disclosed
- 2026-06-09: advisory
- 2026-07-30: patched: Updated advisory with patch information

## References

- [https://spring.io/security/cve-2026-41839](https://spring.io/security/cve-2026-41839)
- [https://github.com/spring-projects/spring-framework/issues/36742](https://github.com/spring-projects/spring-framework/issues/36742)
- [https://github.com/spring-projects/spring-framework/issues/36743](https://github.com/spring-projects/spring-framework/issues/36743)
- [https://github.com/spring-projects/spring-framework/commit/b8ddd2c690fe3f00bb5e3d9f913a37504aab49a0](https://github.com/spring-projects/spring-framework/commit/b8ddd2c690fe3f00bb5e3d9f913a37504aab49a0)
- [https://github.com/spring-projects/spring-framework/commit/d72da90d3a562632e2b565113813f7b4a31f8717](https://github.com/spring-projects/spring-framework/commit/d72da90d3a562632e2b565113813f7b4a31f8717)

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