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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Eclipse Foundation | Eclipse Jetty | 12.1.0 – ≤ 12.1.11, 12.0.0 – ≤ 12.0.37, 11.0.0 – ≤ 11.0.31, 10.0.0 – ≤ 10.0.31 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | jetty12 | 12.0.39-1 | — |
| Debian 13 | jetty12 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | jetty9 +1 | No fix yet | — |
| Ubuntu 26.04 LTS | jetty9 +1 | No fix yet | — |
| Ubuntu 24.04 LTS | jetty9 | No fix yet | — |
| Ubuntu 22.04 LTS | jetty9 | No fix yet | — |
| Ubuntu 20.04 LTS | jetty9 | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | jetty9 | No fix yet | — |
| Ubuntu 16.04 LTS | jetty9 | No fix yet | — |
Advisories 1
- WID-SEC-2026-3233 Eclipse Jetty: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Sep 7, 2026