CVE-2026-59901
High
Description
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.
SeverityHigh
CVSS7.5
Exploit probability—
ProductNetty
PublishedJul 29, 2026
First seenJul 29, 2026
Weakness typeCWE-835CWE-835
How to fix
Update
- netty netty4.1.136, 4.2.16 or later
- io.netty:netty-codec-compression4.2.16.Final or later
- io.netty:netty-codec4.1.136.Final or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| netty netty | v < 4.1.136, 4.2.0 ≤ v < 4.2.16 | 4.1.136, 4.2.16 |
| io.netty:netty-codec-compressionMaven | 4.2.0.Final ≤ v < 4.2.16.Final | 4.2.16.Final |
| io.netty:netty-codecMaven | v < 4.1.136.Final | 4.1.136.Final |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
In the Intelligence 360 plan
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.