VulnerabilityDeferred

CVE-2026-19204

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.

HIGH 8.7EPSS 0.29%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 4.0: 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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/M
EPSS: 0.29% probability · 22th percentile
CISA KEV: Not listed
Weakness: CWE-770, CWE-789
Source: emo@eclipse.org

References

https://github.com/jetty/jetty.project/security/advisories/GHSA-85fq-fc5f-7j7g

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.