Vulnerability-Lookup

GHSA-563Q-J3CM-6JXM

Vulnerability from github – Published: 2026-06-15 20:46 – Updated: 2026-06-15 20:46

Summary

Netty susceptible to HTTP/2 Reset Attack with different on-the-wire signature

Details

Summary

Netty HTTP/2 max header size handling produces attack similar to HTTP/2 Rapid Reset.

Details

There is a setting in the http2 specification called SETTINGS_MAX_HEADER_LIST_SIZE. According to the RFC: “This advisory setting informs a peer of the maximum field section size that the sender is prepared to accept, in units of octets.”

When a client sends that setting to Netty, it appears that Netty will behave as follows:

Read the request
Proxy the request to the origin
Attempt to produce a response
Create an exception while writing the headers for the response

Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature.

Remediation

When speaking with clients, Netty should potentially treat this as “advisory” and ignore it. It would be best to ignore the SETTINGS_MAX_HEADER_LIST_SIZE setting from clients (or ignore it when sending to clients). According to the spec, a server does not need to honor this advisory setting, and it appears that other http/2 implementations ignore it when acting as a server.

Impact

This is a DDoS attack similar to the HTTP/2 Rapid Reset Attack.

Credit

Jonathan Looney (Engineering, Netflix)

Contact

Ashley Tolbert (Security, Netflix) - artolbert@netflix.com

Severity

5.3 (Medium)


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

6.9 (Medium)


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

Show details on source website

JSON

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.2.14.Final"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-codec-http2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.2.0.Final"
            },
            {
              "fixed": "4.2.15.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.1.134.Final"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-codec-http2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.1.135.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-50560"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-15T20:46:56Z",
    "nvd_published_at": "2026-06-12T16:16:32Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nNetty HTTP/2 max header size handling produces attack similar to HTTP/2 Rapid Reset.\n\n### Details\n\nThere is a setting in the http2 specification called `SETTINGS_MAX_HEADER_LIST_SIZE`. According to[ the RFC](https://www.rfc-editor.org/rfc/rfc9113.html#name-defined-settings): \u201cThis advisory setting informs a peer of the maximum field section size that the sender is prepared to accept, in units of octets.\u201d\n\nWhen a client sends that setting to Netty, it appears that Netty will behave as follows:\n\n- Read the request\n- Proxy the request to the origin\n- Attempt to produce a response\n- Create an exception while writing the headers for the response\n\nFunctionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature.\n\n## Remediation\n\nWhen speaking with clients, Netty should potentially treat this as \u201cadvisory\u201d and ignore it.  It would be best to ignore the SETTINGS_MAX_HEADER_LIST_SIZE setting from clients (or ignore it when sending to clients). According to the spec, a server does not need to honor this advisory setting, and it appears that other http/2 implementations ignore it when acting as a server.\n\n### Impact\n\nThis is a DDoS attack similar to the HTTP/2 Rapid Reset Attack.\n\n## Credit\nJonathan Looney (Engineering, Netflix)\n\n## Contact\nAshley Tolbert (Security, Netflix) - artolbert@netflix.com",
  "id": "GHSA-563q-j3cm-6jxm",
  "modified": "2026-06-15T20:46:56Z",
  "published": "2026-06-15T20:46:56Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-563q-j3cm-6jxm"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50560"
    },
    {
      "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"
    },
    {
      "type": "WEB",
      "url": "https://www.rfc-editor.org/rfc/rfc9113.html#name-defined-settings"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Netty susceptible to HTTP/2 Reset Attack with different on-the-wire signature"
}

CVE-2026-50560 (GCVE-0-2026-50560)

Vulnerability from cvelistv5 – Published: 2026-06-12 14:59 – Updated: 2026-06-13 03:21

Title

Netty susceptible to HTTP/2 Reset Attack with different on-the-wire signature

Summary

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty HTTP/2 max header size handling produces an attack similar to HTTP/2 Rapid Reset. There is a setting in the http2 specification called `SETTINGS_MAX_HEADER_LIST_SIZE`. When a client sends that setting to Netty, it appears that Netty will behave as follows: read the request; proxy the request to the origin; attempt to produce a response; and create an exception while writing the headers for the response. Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Severity

6.9 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-770 - Allocation of Resources Without Limits or Throttling

Assigner

GitHub_M

References

4 references

URL	Tags
https://github.com/netty/netty/security/advisorie…	x_refsource_CONFIRM
https://github.com/netty/netty/releases/tag/netty…	x_refsource_MISC
https://github.com/netty/netty/releases/tag/netty…	x_refsource_MISC
https://www.rfc-editor.org/rfc/rfc9113.html#name-…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
netty	netty	Affected: >= 4.2.0.Final, < 4.2.15.Final Affected: < 4.1.135.Final

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-50560",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-13T03:21:03.194740Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-13T03:21:17.132Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "netty",
          "vendor": "netty",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 4.2.0.Final, \u003c 4.2.15.Final"
            },
            {
              "status": "affected",
              "version": "\u003c 4.1.135.Final"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty HTTP/2 max header size handling produces an attack similar to HTTP/2 Rapid Reset. There is a setting in the http2 specification called `SETTINGS_MAX_HEADER_LIST_SIZE`. When a client sends that setting to Netty, it appears that Netty will behave as follows: read the request; proxy the request to the origin; attempt to produce a response; and create an exception while writing the headers for the response. Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature. Versions 4.1.135.Final and 4.2.15.Final patch the issue."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-12T14:59:59.901Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/netty/netty/security/advisories/GHSA-563q-j3cm-6jxm",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/netty/netty/security/advisories/GHSA-563q-j3cm-6jxm"
        },
        {
          "name": "https://github.com/netty/netty/releases/tag/netty-4.1.135.Final",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/netty/netty/releases/tag/netty-4.1.135.Final"
        },
        {
          "name": "https://github.com/netty/netty/releases/tag/netty-4.2.15.Final",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/netty/netty/releases/tag/netty-4.2.15.Final"
        },
        {
          "name": "https://www.rfc-editor.org/rfc/rfc9113.html#name-defined-settings",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://www.rfc-editor.org/rfc/rfc9113.html#name-defined-settings"
        }
      ],
      "source": {
        "advisory": "GHSA-563q-j3cm-6jxm",
        "discovery": "UNKNOWN"
      },
      "title": "Netty susceptible to HTTP/2 Reset Attack with different on-the-wire signature"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-50560",
    "datePublished": "2026-06-12T14:59:59.901Z",
    "dateReserved": "2026-06-04T21:34:34.426Z",
    "dateUpdated": "2026-06-13T03:21:17.132Z",
    "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.

Action not permitted

GHSA-563Q-J3CM-6JXM

Summary

Details

Remediation

Impact

Credit

Contact

CVE-2026-50560 (GCVE-0-2026-50560)

Tags

Sightings

Nomenclature