high7.5
CVE-2026-59901
Netty: [Bzip2Decoder] Infinite Loop in RLE State Machine Leads to Event-Loop Thread Hang
Impact
Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, the `Bzip2Decoder` handler in Netty's compression codec pipeline is vulnerable to a denial-of-service attack through a malformed bzip2 stream that permanently captures the event-loop thread in an infinite loop. The vulnerability exists in the run-length encoding (RLE) state machine within [`Bzip2BlockDecompressor.read()`]. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| maven | io.netty:netty-codec-compression | >= 4.2.0.Final, < 4.2.16.Final | 4.2.16.Final |
| maven | io.netty:netty-codec | < 4.1.136.Final | 4.1.136.Final |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Netty | Netty | before 4.1.136 from 4.2.0 before 4.2.16 |