CVE-2026-41838 Spring Framework Predictable Session ID in WebSocket Module
Attackers can predict WebSocket session IDs to bypass authorization controls in applications using the Spring Framework WebSocket module.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-41838?
CVE-2026-41838 is a medium-severity vulnerability in Vmware Spring Framework, published on 9 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
IDs for WebSocket sessions in the spring-websocket module are not cryptographically unpredictable, which may be possible to exploit in combination with inadequate authorization rules.
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-330
Which versions are affected by CVE-2026-41838?
8 open source packages ship an affected version, including org.springframework:spring-websocket. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.springframework:spring-websocket Maven | All versions to 5.3.48 | None |
org.springframework:spring-websocket Maven | All versions to 5.3.48 | None |
org.springframework:spring-websocket Maven | From 6.1.0 to 6.1.27 | None |
org.springframework:spring-websocket Maven | From 6.1.0 to 6.1.27 | None |
org.springframework:spring-websocket Maven | From 6.2.0 | 6.2.19 |
org.springframework:spring-websocket Maven | From 6.2.0 | 6.2.19 |
2 more packages
org.springframework:spring-websocket Maven | From 7.0.0 | 7.0.8 |
org.springframework:spring-websocket Maven | From 7.0.0 | 7.0.8 |
Products include Vmware Spring Framework.
How do I fix CVE-2026-41838?
Upgrade org.springframework:spring-websocket to a fixed version for your release line: 6.2.19 or 7.0.8.
Is CVE-2026-41838 being exploited?
There is no known exploitation of CVE-2026-41838 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 CLSA-2026-1783645402, CLSA-2026-1787559106, DEBIAN-CVE-2026-41838, ECHO-e4f7-3cd4-8c4e, GHSA-q723-847q-5g8g, UBUNTU-CVE-2026-41838.