CVE-2026-19204

8.7 highEPSS 0.5%

High (8.7). EPSS 0.5% chance of exploitation in the next 30 days.

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.

Severity

CVSS 4.0

8.7 high

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

EPSS: 0.5% chance of exploitation in the next 30 days; higher than 39% of CVEs (scores of 2026-10-31)
CWEs: CWE-770, CWE-789
Published: 2026-09-07
Modified: 2026-09-08
Record from: the NVD, synced 2026-10-19

References

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

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