Vulnerabilities in pkg:maven/io.netty/netty-transport-native-kqueue

PACKAGE
Advisory Identifier: GHSA-w573-9ffj-6ff9
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Advisory Summary

CVE-2026-45536 is a MODERATE (CVSS 4.0) unix-socket fd receive leaks descriptors vulnerability (CWE-772: Missing Release of Resource after Effective Lifetime) affecting Netty libraries in the Maven ecosystem. The issue involves unix-socket fd receive leaks descriptors when peer sends two at once. Remediation is available by upgrading affected packages to version 4.2.15.Final, 4.1.135.Final.

1 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:maven/io.netty/netty-transport-native-kqueue

1 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:maven/io.netty/netty-transport-native-kqueue. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-w573-9ffj-6ff9 CVE-2026-45536 MODERATE Netty: Unix-socket fd receive leaks descriptors when peer sends two at once

CVE-2026-45536 at a Glance

CVE Identifier CVE-2026-45536
GHSA Identifier GHSA-w573-9ffj-6ff9
Severity MODERATE
CVSS v3.1 Base Score 4.0
CWE Classification CWE-772: Missing Release of Resource after Effective Lifetime
Affected Product Netty
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 4.0

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability Low (A:L)

How to Fix CVE-2026-45536

To remediate this vulnerability, upgrade all affected Netty dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

io.netty:netty-transport-native-epoll fixed: 4.2.15.Final 
<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-transport-native-epoll</artifactId>
    <version>4.2.15.Final</version>
</dependency>
io.netty:netty-transport-native-kqueue fixed: 4.2.15.Final 
<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-transport-native-kqueue</artifactId>
    <version>4.2.15.Final</version>
</dependency>
io.netty:netty-transport-native-kqueue fixed: 4.1.135.Final 
<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-transport-native-kqueue</artifactId>
    <version>4.1.135.Final</version>
</dependency>
io.netty:netty-transport-native-epoll fixed: 4.1.135.Final 
<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-transport-native-epoll</artifactId>
    <version>4.1.135.Final</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=io.netty

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-45536, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=io.netty

Analyze the terminal output to locate any version of Netty in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.2.15.Final), your application is affected.

Note: The mvn dependency:tree -Dincludes=io.netty command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-772: Missing Release of Resource after Effective Lifetime, where the product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed. In Netty, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

netty_unix_socket_recvFd sets msg_control to `char control[CMSG_SPACE(sizeof(int))]` (line 940) — 24 bytes on 64-bit Linux. A peer-sent SCM_RIGHTS cmsg carrying two ints has cmsg_len = CMSG_LEN(8) = 24, which fits exactly with no MSG_CTRUNC, so the kernel installs both fds in the receiving process. The subsequent check `cmsg->cmsg_len == CMSG_LEN(sizeof(int))` (line 972, expected 20) fails, the branch that would read the fd is skipped, and neither installed fd is closed. The for(;;) loop calls recvmsg again (non-blocking → EAGAIN → Java maps to 0 → read loop exits normally), leaving two leaked fds per message. There is no MSG_CTRUNC handling. Reachable via Epoll/KQueue DomainSocketChannel when the application opts into DomainSocketReadMode.FILE_DESCRIPTORS (non-default).

CVE-2026-45536 Affected Netty Versions

4 component(s)
Fixed Versions:
4.2.15.Final4.1.135.Final
Product / Package Ecosystem Affected Versions Fixed Version
io.netty:netty-transport-native-epoll
maven/io.netty/netty-transport-native-epoll
Maven
≥ 4.2.0.Final
< 4.2.15.Final
4.2.15.Final
io.netty:netty-transport-native-kqueue
maven/io.netty/netty-transport-native-kqueue
Maven
≥ 4.2.0.Final
< 4.2.15.Final
4.2.15.Final
io.netty:netty-transport-native-kqueue
maven/io.netty/netty-transport-native-kqueue
Maven
< 4.1.135.Final
4.1.135.Final
io.netty:netty-transport-native-epoll
maven/io.netty/netty-transport-native-epoll
Maven
< 4.1.135.Final
4.1.135.Final

References

GitHub Advisory / Wiki ADVISORY
https://github.com/netty/netty/security/advisories/GHSA-w573-9ffj-6ff9
NVD — CVE-2026-45536 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-45536
Netty Source Repository REPOSITORY
https://github.com/netty/netty
Netty Release RELEASE
https://github.com/netty/netty/releases/tag/netty-4.1.135.Final
Netty Release RELEASE
https://github.com/netty/netty/releases/tag/netty-4.2.15.Final

Frequently Asked Questions

What is CVE-2026-45536?
CVE-2026-45536 is a security vulnerability in Netty involving Unix-socket fd receive leaks descriptors when peer sends two at once under CWE-772: Missing Release of Resource after Effective Lifetime.
Which Netty versions are affected?
Affected versions include releases prior to 4.2.15.Final, 4.1.135.Final across affected packages: io.netty:netty-transport-native-epoll, io.netty:netty-transport-native-kqueue.
What version fixes CVE-2026-45536?
Upgrading to 4.2.15.Final, 4.1.135.Final (or the latest patched release for your respective branch) resolves the vulnerability.
Is netty-transport-native-epoll affected?
Yes, io.netty:netty-transport-native-epoll is affected in releases prior to 4.2.15.Final, 4.1.135.Final. Upgrade your dependency to 4.2.15.Final, 4.1.135.Final or later.
Is netty-transport-native-kqueue affected?
Yes, io.netty:netty-transport-native-kqueue is affected in releases prior to 4.2.15.Final, 4.1.135.Final. Upgrade your dependency to 4.2.15.Final, 4.1.135.Final or later.
What is the CVSS score of CVE-2026-45536?
CVE-2026-45536 has a CVSS v3.1 base score of 4.0 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2026-45536?
CVE-2026-45536 is classified under CWE-772: Missing Release of Resource after Effective Lifetime (The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.).
How can I check Maven dependencies for CVE-2026-45536?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=io.netty'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-w573-9ffj-6ff9",
  "modified" : "2026-06-12T19:29:26Z",
  "published" : "2026-06-08T23:01:33Z",
  "aliases" : [ "CVE-2026-45536" ],
  "summary" : "Netty: Unix-socket fd receive leaks descriptors when peer sends two at once",
  "details" : "netty_unix_socket_recvFd sets msg_control to `char control[CMSG_SPACE(sizeof(int))]` (line 940) — 24 bytes on 64-bit Linux. A peer-sent SCM_RIGHTS cmsg carrying two ints has cmsg_len = CMSG_LEN(8) = 24, which fits exactly with no MSG_CTRUNC, so the kernel installs both fds in the receiving process. The subsequent check `cmsg->cmsg_len == CMSG_LEN(sizeof(int))` (line 972, expected 20) fails, the branch that would read the fd is skipped, and neither installed fd is closed. The for(;;) loop calls recvmsg again (non-blocking → EAGAIN → Java maps to 0 → read loop exits normally), leaving two leaked fds per message. There is no MSG_CTRUNC handling. Reachable via Epoll/KQueue DomainSocketChannel when the application opts into DomainSocketReadMode.FILE_DESCRIPTORS (non-default).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "io.netty:netty-transport-native-epoll"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.2.0.Final"
      }, {
        "fixed" : "4.2.15.Final"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 4.2.14.Final"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "io.netty:netty-transport-native-kqueue"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.2.0.Final"
      }, {
        "fixed" : "4.2.15.Final"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 4.2.14.Final"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "io.netty:netty-transport-native-kqueue"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.1.135.Final"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 4.1.134.Final"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "io.netty:netty-transport-native-epoll"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.1.135.Final"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 4.1.134.Final"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/netty/netty/security/advisories/GHSA-w573-9ffj-6ff9"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-45536"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/netty/netty"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/netty/netty/releases/tag/netty-4.1.135.Final"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/netty/netty/releases/tag/netty-4.2.15.Final"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200", "CWE-772" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-08T23:01:33Z",
    "nvd_published_at" : "2026-06-12T15:16:27Z"
  }
}