CVE-2026-108748 (CVSS 5.3)

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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CVSS v3.1 Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS — Exploit Prediction

0.0030

Probability of exploitation

0.21%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-401 CWE-401

References

Other References

https://github.com/quarkiverse/quarkus-langchain4j 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/blob/658ac8268e1a453a6a2066952d9495fb925479e3/chat-scopes/websocket/runtime/src/main/java/io/quarkiverse/langchain4j/chatscopes/websocket/internal/ChatRouteEndpoint.java#L122-L160 https://hackmd.io/@haind/quarkus-langchain4j-chatscope-orphan-leak https://www.vulncheck.com/advisories/quarkus-langchain4j-1.9.0-through-1.14.1-memory-exhaustion-via-chat-routes-websocket https://hackmd.io/@haind/quarkus-langchain4j-chatscope-orphan-leak

Frequently Asked Questions

What is CVE-2026-108748? +

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. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-108748? +

CVE-2026-108748 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0030, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-108748? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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