CVE-2026-41839 Spring Framework Escalation via Session Fixation in WebFlux
Attackers can hijack user sessions in Spring WebFlux applications by exploiting session fixation vulnerabilities, leading to account takeover.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-41839?
CVE-2026-41839 is a medium-severity authentication bypass vulnerability in Vmware Spring Framework, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
A WebFlux application with a compromised subdomain (for example, compromised via cross-site scripting (XSS)) is vulnerable to an escalation attack exchanging a known session ID for that of an authenticated user.
Affected versions: 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.
Weakness: CWE-384
Which versions are affected by CVE-2026-41839?
8 open source packages ship an affected version, including org.springframework:spring-webflux. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.springframework:spring-webflux Maven | All versions to 5.3.39 | None |
org.springframework:spring-webflux Maven | All versions to 5.3.39 | None |
org.springframework:spring-webflux Maven | From 6.1.0 to 6.1.21 | None |
org.springframework:spring-webflux Maven | From 6.1.0 to 6.1.21 | None |
org.springframework:spring-webflux Maven | From 6.2.0 | 6.2.19 |
org.springframework:spring-webflux Maven | From 6.2.0 | 6.2.19 |
2 more packages
org.springframework:spring-webflux Maven | From 7.0.0 | 7.0.8 |
org.springframework:spring-webflux Maven | From 7.0.0 | 7.0.8 |
Products include Vmware Spring Framework.
How do I fix CVE-2026-41839?
Upgrade org.springframework:spring-webflux to a fixed version for your release line: 6.2.19 or 7.0.8.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-41839 being exploited?
There is no known exploitation of CVE-2026-41839 in the wild and no public exploit code.
Other vulnerabilities in Vmware Spring Framework
- CVE-2026-47884 Spring Framework Improper Path Limitation in XsltView
- CVE-2026-47890 Spring Framework Server Sent Event stream corruption while rendering fragments
- CVE-2026-47891 Spring Framework maxInMemorySize Bypassed in Jaxb2Decoder
- CVE-2026-47892 Spring Framework Header Predicate Bypass in WebFlux Functional Endpoints
- CVE-2026-59313 Server Sent Event stream corruption in Spring MVC functional web framework
Sources
Also known as CLEANSTART-2026-FH40291, CLSA-2026-1787647544, DEBIAN-CVE-2026-41839, ECHO-9983-5798-a1fb, GHSA-4hfh-6x8g-gwpp, MINI-57jf-2fcg-3prr and 2 more.