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.
References6
- github.com/quarkiverse/quarkus-langchain4j
- github.com/quarkiverse/quarkus-langchain4j/blob/658ac8268e1a453…
- github.com/quarkiverse/quarkus-langchain4j/blob/658ac8268e1a453…
- hackmd.io/@haind/quarkus-langchain4j-chatscope-orphan-leak
- www.vulncheck.com/advisories/quarkus-langchain4j-1.9.0-through-…
- hackmd.io/@haind/quarkus-langchain4j-chatscope-orphan-leak
Metrics
- CVSS 3.1
-
5.3
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - CVSS 4.0
-
6.9
MEDIUM
Score source: CNA
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 31 · as of 11 November 2026
- CWE
- CWE-401
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.