Quarkus LangChain4j 1.9.0 through 1.14.1 Memory Exhaustion via /_chat/routes WebSocket

Advisories

Quarkus LangChain4j 1.9.0 through 1.14.1 Memory Exhaustion via /_chat/routes WebSocket

severity: medium
date: 10/11/2026
Affecting: quarkus-langchain4j >= 1.9.0, <= 1.14.1
CVE: CVE-2026-108748
CWE: CWE-401 Missing Release of Memory after Effective Lifetime
CVSS: 6.9
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
References: https://hackmd.io/@haind/quarkus-langchain4j-chatscope-orphan-leak
https://github.com/quarkiverse/quarkus-langchain4j/blob/658ac8268e1a453a6a2066952d9495fb925479e3/chat-scopes/websocket/runtime/src/main/java/io/quarkiverse/langchain4j/chatscopes/websocket/internal/ChatRouteEndpoint.java#L122-L160
https://github.com/quarkiverse/quarkus-langchain4j/blob/658ac8268e1a453a6a2066952d9495fb925479e3/chat-scopes/core/runtime/src/main/java/io/quarkiverse/langchain4j/chatscopes/internal/ChatScopeManagedContext.java#L297-L311
https://github.com/quarkiverse/quarkus-langchain4j
Credit: HaiND from the Post and Telecommunication Institute of Technology
Description: Quarkus LangChain4j 1.9.0 through 1.14.1 contains a missing release of memory vulnerability in the chat-scopes WebSocket /_chat/routes endpoint that allows unauthenticated remote clients to exhaust server memory. Attackers can send repeated CONNECT frames reusing one chatId, leaving orphaned scopes in activeScopes until the JVM exits and degrading availability.

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