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Advisory details: gitlab / maven/io.netty/netty-codec/CVE-2026-59901
Advisory ID gitlab/maven/io.netty/netty-codec/CVE-2026-59901
Aliases CVE-2026-59901
GHSA-558v-64gr-wgg4
Summary Netty: [Bzip2Decoder] Infinite Loop in RLE State Machine Leads to Event-Loop Thread Hang 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()`]
Status Published
Exploitability 0.5
Weighted Severity 0.0
Risk
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (3)
CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
cvssv3.1 https://gitlab.com/gitlab-org/advisories-community/-/blob/main/maven/io.netty/netty-codec/CVE-2026-59901.yml
Reference id Reference type URL
https://github.com/netty/netty/releases/tag/netty-4.1.136.Final
https://github.com/netty/netty/releases/tag/netty-4.2.16.Final
https://github.com/netty/netty/security/advisories/GHSA-558v-64gr-wgg4
CVE-2026-59901 https://nvd.nist.gov/vuln/detail/CVE-2026-59901
GHSA-558v-64gr-wgg4 https://github.com/advisories/GHSA-558v-64gr-wgg4
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://gitlab.com/gitlab-org/advisories-community/-/blob/main/maven/io.netty/netty-codec/CVE-2026-59901.yml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: SSVCv2/E:N/A:Y/T:P/P:M/B:A/M:M/D:T/2026-07-29T18:09:34Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/59xxx/CVE-2026-59901.json

Source Advisory: vulnrichment/CVE-2026-59901

View SSVC decision tree 
[{'Exploitation': 'none'},
 {'Automatable': 'yes'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]