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PYSEC-2026-899

Vulnerability from pysec - Published: 2026-07-07 10:17 - Updated: 2026-07-07 11:31
VLAI
Details

Summary

A message parsing and memory management vulnerability in ProtocolBuffer’s C++ and Python implementations can trigger an out of memory (OOM) failure when processing a specially crafted message, which could lead to a denial of service (DoS) on services using the libraries.

Reporter: ClusterFuzz

Affected versions: All versions of C++ Protobufs (including Python) prior to the versions listed below.

Severity & Impact

As scored by google
Medium 5.7 - CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Asscored byt NIST
High 7.5 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

A small (~500 KB) malicious payload can be constructed which causes the running service to allocate more than 3GB of RAM.

Proof of Concept

For reproduction details, please refer to the unit test that identifies the specific inputs that exercise this parsing weakness.

Mitigation / Patching

Please update to the latest available versions of the following packages: - protobuf-cpp (3.18.3, 3.19.5, 3.20.2, 3.21.6) - protobuf-python (3.18.3, 3.19.5, 3.20.2, 4.21.6)

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Impacted products
Name purl
protobuf pkg:pypi/protobuf
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "protobuf",
        "purl": "pkg:pypi/protobuf"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.18.3"
            },
            {
              "introduced": "3.19.0"
            },
            {
              "fixed": "3.19.5"
            },
            {
              "introduced": "3.20.0"
            },
            {
              "fixed": "3.20.2"
            },
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "4.21.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.0.0beta",
        "2.0.3",
        "2.3.0",
        "2.4.1",
        "2.5.0",
        "2.6.0",
        "2.6.1",
        "3.0.0",
        "3.0.0a2",
        "3.0.0a3",
        "3.0.0b1",
        "3.0.0b1.post1",
        "3.0.0b1.post2",
        "3.0.0b2",
        "3.0.0b2.post1",
        "3.0.0b2.post2",
        "3.0.0b3",
        "3.0.0b4",
        "3.1.0",
        "3.1.0.post1",
        "3.10.0",
        "3.10.0rc1",
        "3.11.0",
        "3.11.0rc1",
        "3.11.0rc2",
        "3.11.1",
        "3.11.2",
        "3.11.3",
        "3.12.0",
        "3.12.0rc1",
        "3.12.0rc2",
        "3.12.1",
        "3.12.2",
        "3.12.4",
        "3.13.0",
        "3.13.0rc3",
        "3.14.0",
        "3.14.0rc1",
        "3.14.0rc2",
        "3.14.0rc3",
        "3.15.0",
        "3.15.0rc1",
        "3.15.0rc2",
        "3.15.1",
        "3.15.2",
        "3.15.3",
        "3.15.4",
        "3.15.5",
        "3.15.6",
        "3.15.7",
        "3.15.8",
        "3.16.0",
        "3.16.0rc1",
        "3.16.0rc2",
        "3.17.0",
        "3.17.0rc1",
        "3.17.0rc2",
        "3.17.1",
        "3.17.2",
        "3.17.3",
        "3.18.0",
        "3.18.0rc1",
        "3.18.0rc2",
        "3.18.1",
        "3.19.0",
        "3.19.1",
        "3.19.2",
        "3.19.3",
        "3.19.4",
        "3.2.0",
        "3.2.0rc1",
        "3.2.0rc1.post1",
        "3.2.0rc2",
        "3.20.0",
        "3.20.1",
        "3.20.1rc1",
        "3.3.0",
        "3.4.0",
        "3.5.0.post1",
        "3.5.1",
        "3.5.2",
        "3.5.2.post1",
        "3.6.0",
        "3.6.1",
        "3.7.0",
        "3.7.0rc2",
        "3.7.0rc3",
        "3.7.1",
        "3.8.0",
        "3.8.0rc1",
        "3.9.0",
        "3.9.0rc1",
        "3.9.1",
        "3.9.2",
        "4.21.0",
        "4.21.0rc1",
        "4.21.0rc2",
        "4.21.1",
        "4.21.2",
        "4.21.3",
        "4.21.4",
        "4.21.5"
      ]
    }
  ],
  "aliases": [
    "CVE-2022-1941",
    "GHSA-8gq9-2x98-w8hf"
  ],
  "details": "### Summary\n\nA message parsing and memory management vulnerability in ProtocolBuffer\u2019s C++ and Python implementations can trigger an out of memory (OOM) failure when processing a specially crafted message, which could lead to a denial of service (DoS) on services using the libraries.\n\nReporter: [ClusterFuzz](https://google.github.io/clusterfuzz/)\n\nAffected versions: All versions of C++ Protobufs (including Python) prior to the versions listed below.\n\n### Severity \u0026 Impact\nAs scored by google  \n**Medium 5.7** - [CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H](https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)  \nAsscored byt NIST  \n**High 7.5** - [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H](https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)\n\nA small (~500 KB) malicious payload can be constructed which causes the running service to allocate more than 3GB of RAM.\n\n### Proof of Concept\n\nFor reproduction details, please refer to the unit test that identifies the specific inputs that exercise this parsing weakness.\n\n### Mitigation / Patching\n\nPlease update to the latest available versions of the following packages:\n- protobuf-cpp (3.18.3, 3.19.5, 3.20.2, 3.21.6)\n- protobuf-python (3.18.3, 3.19.5, 3.20.2, 4.21.6)",
  "id": "PYSEC-2026-899",
  "modified": "2026-07-07T11:31:01.754213Z",
  "published": "2026-07-07T10:17:22.281659Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/protocolbuffers/protobuf/security/advisories/GHSA-8gq9-2x98-w8hf"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-1941"
    },
    {
      "type": "WEB",
      "url": "https://cloud.google.com/support/bulletins#GCP-2022-019"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/protocolbuffers/protobuf"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2023/04/msg00019.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CBAUKJQL6O4TIWYBENORSY5P43TVB4M3"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MPCGUT3T5L6C3IDWUPSUO22QDCGQKTOP"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/CBAUKJQL6O4TIWYBENORSY5P43TVB4M3"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MPCGUT3T5L6C3IDWUPSUO22QDCGQKTOP"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20240705-0001"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2022/09/27/1"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/protobuf"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-8gq9-2x98-w8hf"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "protobuf-cpp and protobuf-python have potential Denial of Service issue"
}



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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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