UBUNTU-CVE-2026-121727 (CVE-2026-121727)

Vulnerability from osv_ubuntu – Published: 2026-11-03 23:17 – Updated: 2026-11-03 23:17 – Source website
VLAI
Details

Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "kore",
            "binary_version": "1.2.3-5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "kore",
        "purl": "pkg:deb/ubuntu/kore@1.2.3-5?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.3-1",
        "1.2.3-2",
        "1.2.3-3",
        "1.2.3-4",
        "1.2.3-5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "kore",
            "binary_version": "3.3.1-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "kore",
        "purl": "pkg:deb/ubuntu/kore@3.3.1-1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.0.0-4",
        "3.3.1-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "kore",
            "binary_version": "4.1.0-6"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "kore",
        "purl": "pkg:deb/ubuntu/kore@4.1.0-6?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.1.0-3",
        "4.1.0-4",
        "4.1.0-4ubuntu1",
        "4.1.0-6"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "kore",
            "binary_version": "4.1.0-6"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "kore",
        "purl": "pkg:deb/ubuntu/kore@4.1.0-6?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.1.0-6"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "kore",
            "binary_version": "4.2.3-2build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.10",
        "name": "kore",
        "purl": "pkg:deb/ubuntu/kore@4.2.3-2build1?arch=source\u0026distro=stonking"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.2.3-2",
        "4.2.3-2build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "kore",
            "binary_version": "4.2.3-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "kore",
        "purl": "pkg:deb/ubuntu/kore@4.2.3-2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.2.3-2"
      ]
    }
  ],
  "aliases": [],
  "details": "Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory.",
  "id": "UBUNTU-CVE-2026-121727",
  "modified": "2026-11-03T23:17:00Z",
  "published": "2026-11-03T23:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-121727"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-121727"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jorisvink/kore"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jorisvink/kore/blob/4.3.0-rc5/src/http.c#L934"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jorisvink/kore/commit/1ff3c0f6f7973dc7fc8bf38369790ef2d8079b3b"
    },
    {
      "type": "REPORT",
      "url": "https://kore.io/releases/4.3.0"
    },
    {
      "type": "REPORT",
      "url": "https://www.vulncheck.com/advisories/kore-before-4.3.0-integer-underflow-memory-exhaustion-via-http-header-recv"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-121727"
  ]
}



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