CVE-2026-108748
MEDIUM 6.9Quarkus 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.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 30th percentile
Impact if exploited
6.9CVSS 4.0 · MEDIUM
- ConfidentialityNone
- IntegrityNone
- AvailabilityLow
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
Search for new PoCs
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Tracked sources are checked daily for recent CVEs, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Data snapshot:
Weakness (CWE)
- CWE-401: Missing Release of Memory after Effective Lifetime
CVSS 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 and research data (JSON)
All CVSS metrics
- MEDIUM 6.9 v4.0 · CNA Primary
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 - MEDIUM 5.3 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - MEDIUM 6.9 v4.0 · NVD Secondary
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 - MEDIUM 5.3 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
References
Exploit-tagged references (not proof of a PoC)
- https://hackmd.io/@haind/quarkus-langchain4j-chatscope-orphan-leak CVE record · VulnCheck · Updated 2026-10-11T12:19:49.295Z
CVE record · CISA-ADP · Updated 2026-10-13T19:45:41.159Z
NVD · CVE-2026-108748 · Updated 2026-10-16T17:25:57.940
Advisories
- https://www.vulncheck.com/advisories/quarkus-langchain4j-1.9.0-through-1.14.1-memory-exhaustion-via-chat-routes-websocket CVE record · VulnCheck · Updated 2026-10-11T12:19:49.295Z
NVD · CVE-2026-108748 · Updated 2026-10-16T17:25:57.940 - https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-96913 EUVD · EUVD-2026-96913
Technical & other
- 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 CVE record · VulnCheck · Updated 2026-10-11T12:19:49.295Z
NVD · CVE-2026-108748 · Updated 2026-10-16T17:25:57.940 - https://github.com/quarkiverse/quarkus-langchain4j/blob/658ac8268e1a453a6a2066952d9495fb925479e3/chat-scopes/core/runtime/src/main/java/io/quarkiverse/langchain4j/chatscopes/internal/ChatScopeManagedContext.java#L297-L311 CVE record · VulnCheck · Updated 2026-10-11T12:19:49.295Z
NVD · CVE-2026-108748 · Updated 2026-10-16T17:25:57.940 - https://github.com/quarkiverse/quarkus-langchain4j CVE record · VulnCheck · Updated 2026-10-11T12:19:49.295Z
NVD · CVE-2026-108748 · Updated 2026-10-16T17:25:57.940