Vulnerability-Lookup

FKIE_CVE-2026-89044

Vulnerability from fkie_nvd - Published: 2026-09-10 18:18 - Updated: 2026-09-16 16:06

Severity

6.5 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Summary

Netty versions 4.1.133.Final through 4.1.137.Final and 4.2.13.Final through 4.2.17.Final fail to properly validate the final transfer coding in the Transfer-Encoding header, allowing attackers to smuggle requests by using malformed encoding declarations. Attackers can split Transfer-Encoding headers across multiple lines or use values like 'chunked, xchunked' to bypass validation and decode messages as chunked when the final coding is not chunked, enabling request smuggling attacks.

References

URL	Tags
disclosure@vulncheck.com	https://github.com/netty/netty	Product
disclosure@vulncheck.com	https://github.com/netty/netty/blob/netty-4.1.137.Final/codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectDecoder.java#L866	Product
disclosure@vulncheck.com	https://github.com/netty/netty/commit/640d4d3324f7b811a4903d0730c8ccb35500500c	Patch
disclosure@vulncheck.com	https://github.com/netty/netty/commit/ca87393b0e9e13c493d213a268e727a6d44e1585	Patch
disclosure@vulncheck.com	https://github.com/netty/netty/releases/tag/netty-4.1.138.Final	Release Notes
disclosure@vulncheck.com	https://github.com/netty/netty/releases/tag/netty-4.2.18.Final	Release Notes
disclosure@vulncheck.com	https://github.com/netty/netty/security/advisories/GHSA-hcvj-94mj-jp5c	Vendor Advisory, Exploit
disclosure@vulncheck.com	https://www.vulncheck.com/advisories/netty-4.1.133-final-through-4.1.137-final-and-4.2.13-final-through-4.2.17-final-http-request-smuggling-via-transfer-encoding	Patch, Third Party Advisory

Impacted products

	Vendor	Product	Version
	netty	netty	*
	netty	netty	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://repo1.maven.org/maven2/io/netty/netty-codec-http/",
          "defaultStatus": "unaffected",
          "packageURL": "pkg:maven/io.netty/netty-codec-http",
          "product": "netty",
          "repo": "https://github.com/netty/netty",
          "vendor": "netty",
          "versions": [
            {
              "lessThan": "4.1.138.Final",
              "status": "affected",
              "version": "4.1.133.Final",
              "versionType": "custom"
            },
            {
              "lessThan": "4.2.18.Final",
              "status": "affected",
              "version": "4.2.13.Final",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "disclosure@vulncheck.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "D2ABD6AF-82BD-40D0-9A03-4101220F39CC",
              "versionEndExcluding": "4.1.138",
              "versionStartIncluding": "4.1.133",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "EC21FA2A-C386-4134-A447-92616A930370",
              "versionEndExcluding": "4.2.18",
              "versionStartIncluding": "4.2.13",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Netty versions 4.1.133.Final through 4.1.137.Final and 4.2.13.Final through 4.2.17.Final fail to properly validate the final transfer coding in the Transfer-Encoding header, allowing attackers to smuggle requests by using malformed encoding declarations. Attackers can split Transfer-Encoding headers across multiple lines or use values like \u0027chunked, xchunked\u0027 to bypass validation and decode messages as chunked when the final coding is not chunked, enabling request smuggling attacks."
    }
  ],
  "id": "CVE-2026-89044",
  "lastModified": "2026-09-16T16:06:07.240",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 2.5,
        "source": "disclosure@vulncheck.com",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 6.9,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "LOW",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-10T18:18:16.243",
  "references": [
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Product"
      ],
      "url": "https://github.com/netty/netty"
    },
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Product"
      ],
      "url": "https://github.com/netty/netty/blob/netty-4.1.137.Final/codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectDecoder.java#L866"
    },
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/netty/netty/commit/640d4d3324f7b811a4903d0730c8ccb35500500c"
    },
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/netty/netty/commit/ca87393b0e9e13c493d213a268e727a6d44e1585"
    },
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Release Notes"
      ],
      "url": "https://github.com/netty/netty/releases/tag/netty-4.1.138.Final"
    },
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Release Notes"
      ],
      "url": "https://github.com/netty/netty/releases/tag/netty-4.2.18.Final"
    },
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Vendor Advisory",
        "Exploit"
      ],
      "url": "https://github.com/netty/netty/security/advisories/GHSA-hcvj-94mj-jp5c"
    },
    {
      "source": "disclosure@vulncheck.com",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://www.vulncheck.com/advisories/netty-4.1.133-final-through-4.1.137-final-and-4.2.13-final-through-4.2.17-final-http-request-smuggling-via-transfer-encoding"
    }
  ],
  "sourceIdentifier": "disclosure@vulncheck.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-444"
        }
      ],
      "source": "disclosure@vulncheck.com",
      "type": "Primary"
    }
  ]
}

CVE-2026-89044 (GCVE-0-2026-89044)

Vulnerability from cvelistv5 – Published: 2026-09-10 17:39 – Updated: 2026-09-10 17:39

Title

Netty 4.1.133.Final through 4.1.137.Final and 4.2.13.Final through 4.2.17.Final HTTP Request Smuggling via Transfer-Encoding

Summary

Severity

6.9 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

6.5 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CWE

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Assigner

VulnCheck mitre root

References

8 references

URL	Tags
https://github.com/netty/netty/security/advisorie…	vendor-advisory
https://github.com/netty/netty/commit/ca87393b0e9…	patch
https://github.com/netty/netty/commit/640d4d3324f…	patch
https://github.com/netty/netty/blob/netty-4.1.137…	technical-description
https://github.com/netty/netty/releases/tag/netty…	release-notes
https://github.com/netty/netty/releases/tag/netty…	release-notes
https://github.com/netty/netty	product
https://www.vulncheck.com/advisories/netty-4.1.13…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
netty	netty	Affected: 4.1.133.Final , < 4.1.138.Final (custom) Affected: 4.2.13.Final , < 4.2.18.Final (custom)

Date Public

2026-07-20 00:00

Credits

Yu Bao, PayPal Cyber Security Team dreamlike-ocean Michael-JRead

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "collectionURL": "https://repo1.maven.org/maven2/io/netty/netty-codec-http/",
          "defaultStatus": "unaffected",
          "packageURL": "pkg:maven/io.netty/netty-codec-http",
          "product": "netty",
          "repo": "https://github.com/netty/netty",
          "vendor": "netty",
          "versions": [
            {
              "lessThan": "4.1.138.Final",
              "status": "affected",
              "version": "4.1.133.Final",
              "versionType": "custom"
            },
            {
              "lessThan": "4.2.18.Final",
              "status": "affected",
              "version": "4.2.13.Final",
              "versionType": "custom"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
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              "cpeMatch": [
                {
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                  "vulnerable": true
                }
              ],
              "negate": false,
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                  "vulnerable": true
                }
              ],
              "negate": false,
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            }
          ]
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      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Yu Bao, PayPal Cyber Security Team"
        },
        {
          "lang": "en",
          "type": "finder",
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        }
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      "descriptions": [
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        }
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      "metrics": [
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          "url": "https://github.com/netty/netty"
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          "tags": [
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          "url": "https://www.vulncheck.com/advisories/netty-4.1.133-final-through-4.1.137-final-and-4.2.13-final-through-4.2.17-final-http-request-smuggling-via-transfer-encoding"
        }
      ],
      "title": "Netty 4.1.133.Final through 4.1.137.Final and 4.2.13.Final through 4.2.17.Final HTTP Request Smuggling via Transfer-Encoding",
      "x_generator": {
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  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-89044",
    "datePublished": "2026-09-10T17:39:34.162Z",
    "dateReserved": "2026-09-10T16:45:13.890Z",
    "dateUpdated": "2026-09-10T17:39:34.162Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.