cve-2026-44248

MEDIUM CVSS 5.3 nvd
Description

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, the MQTT 5 header Properties section is parsed and buffered before any message size limit is applied. Specifically, in MqttDecoder, the decodeVariableHeader() method is called before the bytesRemainingBeforeVariableHeader > maxBytesInMessage check. The decodeVariableHeader() can call other methods which will call decodeProperties(). Effectively, Netty does not apply any limits to the size of the properties being decoded. Additionally, because MqttDecoder extends ReplayingDecoder, Netty will repeatedly re-parse the enormous Properties sections and buffer the bytes in memory, until the entire thing parses to completion. This can cause high resource usage in both CPU and memory. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

Timeline
Published
2026-05-13
Last Modified
2026-09-11
CVSS Details
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
Affected Products
  • netty netty
Weaknesses (CWE)
CWE-400 CWE-770
CVSS metrics
Version Base Severity Vector Exploitability Impact Source
3.1 5.3 MEDIUM CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L 3.9 1.4 security-advisories@github.com
3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 3.9 3.6 nvd@nist.gov
3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 3.9 3.6 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
CPE configurations
OR
CPE Version range Vulnerable
cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* < 4.1.133 yes
cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* >= 4.2.0, < 4.2.13 yes
NVD metadata
NVD status
Modified
Source identifier
security-advisories@github.com
References
Linked Vulnerabilities
cpujul2026csaf csaf_oracle
cspuaug2026csaf csaf_oracle 

{
  "cvss": 5.3,
  "datePublished": "2026-05-13T19:17:27.143",
  "dateUpdated": "2026-09-11T13:18:04.643",
  "description": "Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, the MQTT 5 header Properties section is parsed and buffered before any message size limit is applied. Specifically, in MqttDecoder, the decodeVariableHeader() method is called before the bytesRemainingBeforeVariableHeader > maxBytesInMessage check. The decodeVariableHeader() can call other methods which will call decodeProperties(). Effectively, Netty does not apply any limits to the size of the properties being decoded. Additionally, because MqttDecoder extends ReplayingDecoder, Netty will repeatedly re-parse the enormous Properties sections and buffer the bytes in memory, until the entire thing parses to completion. This can cause high resource usage in both CPU and memory. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.",
  "id": "CVE-2026-44248",
  "raw": {
    "affected": [
      {
        "affectedData": [
          {
            "product": "netty",
            "vendor": "netty",
            "versions": [
              {
                "status": "affected",
                "version": ">= 4.2.0.Alpha1, < 4.2.13.Final"
              },
              {
                "status": "affected",
                "version": "< 4.1.133.Final"
              }
            ]
          },
          {
            "product": "netty-codec-mqtt",
            "vendor": "io.netty",
            "versions": [
              {
                "status": "affected",
                "version": ">= 4.2.0.Alpha1, < 4.2.13.Final"
              },
              {
                "status": "affected",
                "version": "< 4.1.133.Final"
              }
            ]
          }
        ],
        "source": "security-advisories@github.com"
      },
      {
        "affectedData": [
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:amq_broker:7.13"
            ],
            "defaultStatus": "affected",
            "packageName": "netty",
            "product": "Red Hat AMQ Broker 7.13.6",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "codec-mqtt",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:amq_broker:7.14"
            ],
            "defaultStatus": "affected",
            "packageName": "netty",
            "product": "Red Hat AMQ Broker 7.14.1",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "codec-mqtt",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:apache_camel_spring_boot:4.18"
            ],
            "defaultStatus": "affected",
            "packageName": "netty",
            "product": "Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "codec-mqtt",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:jboss_data_grid:8"
            ],
            "defaultStatus": "affected",
            "packageName": "netty",
            "product": "Red Hat Data Grid 8.6.2",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "codec-mqtt",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:jboss_fuse:7"
            ],
            "defaultStatus": "affected",
            "packageName": "netty-codec-mqtt",
            "product": "Red Hat Fuse 7",
            "vendor": "Red Hat"
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:jboss_enterprise_application_platform:7"
            ],
            "defaultStatus": "unaffected",
            "packageName": "netty-codec-mqtt",
            "product": "Red Hat JBoss Enterprise Application Platform 7",
            "vendor": "Red Hat"
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:jbosseapxp"
            ],
            "defaultStatus": "unaffected",
            "packageName": "netty-codec-mqtt",
            "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack",
            "vendor": "Red Hat"
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:jboss_enterprise_bpms_platform:7"
            ],
            "defaultStatus": "affected",
            "packageName": "netty-codec-mqtt",
            "product": "Red Hat Process Automation 7",
            "vendor": "Red Hat"
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:red_hat_single_sign_on:7"
            ],
            "defaultStatus": "unaffected",
            "packageName": "netty-codec-mqtt",
            "product": "Red Hat Single Sign-On 7",
            "vendor": "Red Hat"
          }
        ],
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "DFE205A5-2C43-40C9-A2FF-CF6759B8D861",
                "versionEndExcluding": "4.1.133",
                "vulnerable": true
              },
              {
                "criteria": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "D94A720F-9CED-4BE9-8C37-FD9E2FD28472",
                "versionEndExcluding": "4.2.13",
                "versionStartIncluding": "4.2.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, the MQTT 5 header Properties section is parsed and buffered before any message size limit is applied. Specifically, in MqttDecoder, the decodeVariableHeader() method is called before the bytesRemainingBeforeVariableHeader > maxBytesInMessage check. The decodeVariableHeader() can call other methods which will call decodeProperties(). Effectively, Netty does not apply any limits to the size of the properties being decoded. Additionally, because MqttDecoder extends ReplayingDecoder, Netty will repeatedly re-parse the enormous Properties sections and buffer the bytes in memory, until the entire thing parses to completion. This can cause high resource usage in both CPU and memory. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final."
      }
    ],
    "id": "CVE-2026-44248",
    "lastModified": "2026-09-11T13:18:04.643",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
            "version": "3.1"
          },
          "exploitabilityScore": 3.9,
          "impactScore": 1.4,
          "source": "security-advisories@github.com",
          "type": "Secondary"
        },
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "exploitabilityScore": 3.9,
          "impactScore": 3.6,
          "source": "nvd@nist.gov",
          "type": "Primary"
        },
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "exploitabilityScore": 3.9,
          "impactScore": 3.6,
          "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-44248",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "yes"
              },
              {
                "technicalImpact": "partial"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-05-13T19:11:14.636780Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-05-13T19:17:27.143",
    "references": [
      {
        "source": "security-advisories@github.com",
        "tags": [
          "Vendor Advisory"
        ],
        "url": "https://github.com/netty/netty/security/advisories/GHSA-jfg9-48mv-9qgx"
      },
      {
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "url": "https://access.redhat.com/errata/RHSA-2026:37390"
      },
      {
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "url": "https://access.redhat.com/errata/RHSA-2026:41951"
      },
      {
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "url": "https://access.redhat.com/errata/RHSA-2026:66488"
      },
      {
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "url": "https://access.redhat.com/errata/RHSA-2026:66545"
      },
      {
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "url": "https://access.redhat.com/security/cve/CVE-2026-44248"
      },
      {
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2477231"
      },
      {
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44248.json"
      }
    ],
    "sourceIdentifier": "security-advisories@github.com",
    "vulnStatus": "Modified",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-400"
          }
        ],
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-770"
          }
        ],
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "type": "Secondary"
      }
    ]
  },
  "severity": "MEDIUM",
  "source": "nvd",
  "title": "Netty is an asynchronous, event-driven network application framework"
}
Enrichment data
EPSS
View JSON Download
CISA KEV
View JSON Download
Aggregated bundle (all enrichments)
View JSON API Download bundle
View JSON API Download JSON