CVE-2026-19204: CWE-770 Allocation of resources without limits or throttling in Eclipse Foundation Eclipse Jetty
Description
CVE-2026-19204 is a high-severity vulnerability in Eclipse Jetty where a client can send a WebSocket frame with an unknown opcode and a very large declared payload length. This causes Jetty to allocate a large amount of memory, potentially exhausting the JVM heap. The issue arises when auto-fragmentation is enabled, as unknown opcodes bypass normal frame size checks and payload allocation happens before opcode validation.
CVSS v4.0
Score 8.7high
Affected software
Eclipse Foundation
Eclipse Jetty
pkg:maven/org.eclipse.jetty/jettyRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability in Eclipse Jetty involves improper resource allocation during WebSocket frame processing. When auto-fragmentation is enabled, Jetty does not properly limit or throttle memory allocation for frames with unknown opcodes. A malicious client can exploit this by sending a WebSocket frame declaring a very large payload length with an unknown opcode, causing Jetty to attempt a large memory allocation. This can lead to JVM heap exhaustion and potential denial of service. The flaw is identified as CWE-770 (Allocation of resources without limits or throttling) and CWE-789 (Uncontrolled Memory Allocation).
Potential Impact
Successful exploitation can cause Jetty to exhaust JVM heap memory, leading to denial of service conditions. There is no indication of privilege escalation, data leakage, or code execution from the provided data. The vulnerability affects server availability by resource exhaustion.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the data. Until a patch is available, consider disabling auto-fragmentation if feasible or implementing network-level controls to detect and block suspicious WebSocket frames with unknown opcodes and large payload lengths.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- eclipse
- Date Reserved
- 2026-08-07T07:33:05.744Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a9e940facd9273b4974db50
Added to database: 09/07/2026, 10:38:07 UTC
Last enriched: 09/15/2026, 01:01:53 UTC
Last updated: 10/22/2026, 13:15:20 UTC
Views: 109
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