Vulnerability-Lookup

UBUNTU-CVE-2026-56820 (CVE-2026-56820)

Vulnerability from osv_ubuntu – Published: 2026-07-21 23:17 – Updated: 2026-10-17 09:45 – Source website

Details

Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and prior to 4.1.135.Final, OcspClient does not validate that the CertificateID in an OCSP response matches the requested CertificateID, which can lead to replay attack. OcspClient.validateResponse accepts a legitimately signed GOOD status response for an unrelated certificate issued by the same CA, allowing bypass of revocation checks for another certificate. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

Severity

7.4 (High)


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

9.1 (Critical)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-56820	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-56820	REPORT
	https://github.com/netty/netty/security/advisorie…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnetty-java",
            "binary_version": "1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1"
          }
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      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "netty",
        "purl": "pkg:deb/ubuntu/netty@1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
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    },
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      "ecosystem_specific": {
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            "binary_version": "1:4.0.34-1ubuntu0.1~esm5"
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      },
      "package": {
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      },
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            {
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            }
          ],
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        "1:4.0.32-1",
        "1:4.0.33-1",
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        "1:4.0.34-1ubuntu0.1~esm2",
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        {
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            }
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        "1:4.1.7-4ubuntu0.1",
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        "1:4.1.7-4ubuntu0.1+esm2",
        "1:4.1.7-4ubuntu0.1+esm3",
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            "binary_name": "libnetty-java",
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        "1:4.1.45-1ubuntu0.1~esm2",
        "1:4.1.45-1ubuntu0.1~esm3",
        "1:4.1.45-1ubuntu0.1~esm4",
        "1:4.1.45-1ubuntu0.1~esm6",
        "1:4.1.45-1ubuntu0.1~esm7"
      ]
    },
    {
      "ecosystem_specific": {
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            "binary_version": "1:4.1.48-4+deb11u2ubuntu0.2+esm1"
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        ]
      },
      "package": {
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        "name": "netty",
        "purl": "pkg:deb/ubuntu/netty@1:4.1.48-4+deb11u2ubuntu0.2+esm1?arch=source\u0026distro=esm-apps/jammy"
      },
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            {
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      ],
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        "1:4.1.48-4+deb11u2ubuntu0.1~esm2",
        "1:4.1.48-4+deb11u2ubuntu0.1",
        "1:4.1.48-4+deb11u2ubuntu0.1+esm1",
        "1:4.1.48-4+deb11u2ubuntu0.1+esm3",
        "1:4.1.48-4+deb11u2ubuntu0.2",
        "1:4.1.48-4+deb11u2ubuntu0.2+esm1"
      ]
    },
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      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.1.48-9ubuntu0.2+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:24.04:LTS",
        "name": "netty",
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      },
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        "1:4.1.48-9ubuntu0.1~esm2",
        "1:4.1.48-9ubuntu0.1",
        "1:4.1.48-9ubuntu0.1+esm1",
        "1:4.1.48-9ubuntu0.1+esm3",
        "1:4.1.48-9ubuntu0.2",
        "1:4.1.48-9ubuntu0.2+esm1",
        "1:4.1.48-9ubuntu0.2+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnetty-buffer-java",
            "binary_version": "1:4.1.48-16ubuntu1"
          },
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            "binary_name": "libnetty-common-java",
            "binary_version": "1:4.1.48-16ubuntu1"
          },
          {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.1.48-16ubuntu1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.10",
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      },
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      ]
    },
    {
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            "binary_name": "libnetty-buffer-java",
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            "binary_version": "1:4.1.48-16ubuntu0.1~esm2"
          },
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          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:26.04:LTS",
        "name": "netty",
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      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
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        "1:4.1.48-10",
        "1:4.1.48-11",
        "1:4.1.48-12",
        "1:4.1.48-13",
        "1:4.1.48-14",
        "1:4.1.48-16",
        "1:4.1.48-16ubuntu0.1~esm2"
      ]
    }
  ],
  "aliases": [],
  "details": "Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and prior to 4.1.135.Final, `OcspClient` does not validate that the `CertificateID` in an OCSP response matches the requested `CertificateID`, which can lead to replay attack. `OcspClient.validateResponse` accepts a legitimately signed `GOOD` status response for an unrelated certificate issued by the same CA, allowing bypass of revocation checks for another certificate. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.",
  "id": "UBUNTU-CVE-2026-56820",
  "modified": "2026-10-17T09:45:57Z",
  "published": "2026-07-21T23:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-56820"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-56820"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-272m-gcwp-mpwg"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-56820"
  ]
}

CVE-2026-56820 (GCVE-0-2026-56820)

Vulnerability from cvelistv5 – Published: 2026-07-21 22:26 – Updated: 2026-07-24 20:12

Title

Netty: Missing CertificateID Validation in OCSP Response Allows Replay Attacks

Summary

Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and prior to 4.1.135.Final, `OcspClient` does not validate that the `CertificateID` in an OCSP response matches the requested `CertificateID`, which can lead to replay attack. `OcspClient.validateResponse` accepts a legitimately signed `GOOD` status response for an unrelated certificate issued by the same CA, allowing bypass of revocation checks for another certificate. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

Severity

7.4 (High)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-24 03:55 UTC

CWE

CWE-295 - Improper Certificate Validation

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7627 records in the last 180 days details

References

5 references

URL	Tags
https://github.com/netty/netty/security/advisorie…	x_refsource_CONFIRM
https://github.com/netty/netty/commit/5b68c61f37a…	x_refsource_MISC
https://github.com/netty/netty/commit/bb2ff68a1fb…	x_refsource_MISC
https://github.com/netty/netty/releases/tag/netty…	x_refsource_MISC
https://github.com/netty/netty/releases/tag/netty…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
netty	netty	Affected: >= 4.2.0.Final, < 4.2.16.Final Affected: < 4.1.136.Final

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-56820",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-24T03:55:59.408001Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-24T20:12:43.581Z",
          "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 4.2.16.Final"
            },
            {
              "status": "affected",
              "version": "\u003c 4.1.136.Final"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and prior to 4.1.135.Final, `OcspClient` does not validate that the `CertificateID` in an OCSP response matches the requested `CertificateID`, which can lead to replay attack. `OcspClient.validateResponse` accepts a legitimately signed `GOOD` status response for an unrelated certificate issued by the same CA, allowing bypass of revocation checks for another certificate. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.4,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-295",
              "description": "CWE-295: Improper Certificate Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-21T22:26:16.588Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/netty/netty/security/advisories/GHSA-272m-gcwp-mpwg",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/netty/netty/security/advisories/GHSA-272m-gcwp-mpwg"
        },
        {
          "name": "https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b"
        },
        {
          "name": "https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6"
        },
        {
          "name": "https://github.com/netty/netty/releases/tag/netty-4.1.136.Final",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/netty/netty/releases/tag/netty-4.1.136.Final"
        },
        {
          "name": "https://github.com/netty/netty/releases/tag/netty-4.2.16.Final",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/netty/netty/releases/tag/netty-4.2.16.Final"
        }
      ],
      "source": {
        "advisory": "GHSA-272m-gcwp-mpwg",
        "discovery": "UNKNOWN"
      },
      "title": "Netty: Missing CertificateID Validation in OCSP Response Allows Replay Attacks"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-56820",
    "datePublished": "2026-07-21T22:26:16.588Z",
    "dateReserved": "2026-06-23T14:55:09.116Z",
    "dateUpdated": "2026-07-24T20:12:43.581Z",
    "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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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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.
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