Bug 2529344 (CVE-2026-19204)

Summary: CVE-2026-19204 org.eclipse.jetty.websocket/websocket-core-common: Jetty: Denial of Service via crafted WebSocket frame with unknown opcode
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: anthomas, ehelms, ggainey, gmalinko, janstey, jpasqual, juwatts, mdellweg, mhulan, nmoumoul, osousa, pcreech, pdelbell, rchan, rhel-process-autobot, rstepani, smallamp, tmalecek, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in Jetty. A remote attacker can exploit this vulnerability by sending a specially crafted WebSocket frame with an unknown operation code (opcode) and a very large declared payload length. When auto-fragmentation is enabled, these unknown opcodes bypass the normal maximum frame size handling, leading Jetty to attempt a large memory allocation before validating the opcode. This can cause the Java Virtual Machine (JVM) heap to be exhausted, resulting in a Denial of Service (DoS) for the affected system.
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-07 10:41:37 UTC
A client may send a WebSocket frame with an unknown opcode and a very large declared payload length, causing Jetty to attempt a large memory allocation and potentially exhaust the JVM heap.




This occurs when auto-fragmentation is enabled, as unknown opcodes bypass the normal maximum frame size handling and payload allocation occurs before the opcode is validated.