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.
Published: 2026-07-29
Score: 8.7 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories
Source ID Title
Github GHSA Github GHSA GHSA-558v-64gr-wgg4 Netty: [Bzip2Decoder] Infinite Loop in RLE State Machine Leads to Event-Loop Thread Hang
History

Wed, 29 Jul 2026 18:15:00 +0000

Type Values Removed Values Added
Description A flaw was found in the netty-codec-compression component of Netty. This vulnerability, caused by a logic error in the bzip2 decoder, allows a remote attacker to send specially crafted bzip2-compressed data. Processing this malformed data can trigger an infinite loop, causing the decoder thread to consume excessive CPU resources. This leads to a denial of service (DoS), requiring manual intervention to restore service. 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.
Title io.netty/netty-codec-compression: Netty: Infinite loop in netty-codec-compression (bzip2) Netty Bzip2Decoder: Infinite Loop in RLE State Machine Leads to Event-Loop Thread Hang
References
Metrics cvssV4_0

{'score': 8.7, 'vector': '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'}

Tue, 28 Jul 2026 00:15:00 +0000

Type Values Removed Values Added
Description A flaw was found in the netty-codec-compression component of Netty. This vulnerability, caused by a logic error in the bzip2 decoder, allows a remote attacker to send specially crafted bzip2-compressed data. Processing this malformed data can trigger an infinite loop, causing the decoder thread to consume excessive CPU resources. This leads to a denial of service (DoS), requiring manual intervention to restore service.
Title io.netty/netty-codec-compression: Netty: Infinite loop in netty-codec-compression (bzip2)
Weaknesses CWE-835
References
Metrics threat_severity

None

 cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Important

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-07-29T18:09:41.130Z

Reserved: 2026-07-07T16:40:07.984Z

Link: CVE-2026-59901

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

Severity : Important

Publid Date: 2026-07-09T00:00:00Z

Links: CVE-2026-59901 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses