UBUNTU-CVE-2026-3784 (CVE-2026-3784)

Vulnerability from osv_ubuntu – Published: 2026-03-11 18:00 – Updated: 2026-10-17 09:37 – Source website
VLAI
Details

curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP proxy. The proper behavior is to create or use a separate connection.

Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
N/A (UNKNOWN)
low
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "curl",
            "binary_version": "7.58.0-2ubuntu3.24+esm8"
          },
          {
            "binary_name": "libcurl3-gnutls",
            "binary_version": "7.58.0-2ubuntu3.24+esm8"
          },
          {
            "binary_name": "libcurl3-nss",
            "binary_version": "7.58.0-2ubuntu3.24+esm8"
          },
          {
            "binary_name": "libcurl4",
            "binary_version": "7.58.0-2ubuntu3.24+esm8"
          }
        ],
        "priority_reason": "Upstream defined it as low"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "curl",
        "purl": "pkg:deb/ubuntu/curl@7.58.0-2ubuntu3.24+esm8?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.58.0-2ubuntu3.24+esm8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "7.55.1-1ubuntu2",
        "7.55.1-1ubuntu2.1",
        "7.57.0-1ubuntu1",
        "7.58.0-2ubuntu1",
        "7.58.0-2ubuntu2",
        "7.58.0-2ubuntu3",
        "7.58.0-2ubuntu3.1",
        "7.58.0-2ubuntu3.2",
        "7.58.0-2ubuntu3.3",
        "7.58.0-2ubuntu3.5",
        "7.58.0-2ubuntu3.6",
        "7.58.0-2ubuntu3.7",
        "7.58.0-2ubuntu3.8",
        "7.58.0-2ubuntu3.9",
        "7.58.0-2ubuntu3.10",
        "7.58.0-2ubuntu3.12",
        "7.58.0-2ubuntu3.13",
        "7.58.0-2ubuntu3.14",
        "7.58.0-2ubuntu3.15",
        "7.58.0-2ubuntu3.16",
        "7.58.0-2ubuntu3.17",
        "7.58.0-2ubuntu3.18",
        "7.58.0-2ubuntu3.19",
        "7.58.0-2ubuntu3.20",
        "7.58.0-2ubuntu3.21",
        "7.58.0-2ubuntu3.22",
        "7.58.0-2ubuntu3.23",
        "7.58.0-2ubuntu3.24",
        "7.58.0-2ubuntu3.24+esm1",
        "7.58.0-2ubuntu3.24+esm2",
        "7.58.0-2ubuntu3.24+esm3",
        "7.58.0-2ubuntu3.24+esm4",
        "7.58.0-2ubuntu3.24+esm5",
        "7.58.0-2ubuntu3.24+esm7"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "curl",
            "binary_version": "7.68.0-1ubuntu2.25+esm3"
          },
          {
            "binary_name": "libcurl3-gnutls",
            "binary_version": "7.68.0-1ubuntu2.25+esm3"
          },
          {
            "binary_name": "libcurl3-nss",
            "binary_version": "7.68.0-1ubuntu2.25+esm3"
          },
          {
            "binary_name": "libcurl4",
            "binary_version": "7.68.0-1ubuntu2.25+esm3"
          }
        ],
        "priority_reason": "Upstream defined it as low"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "curl",
        "purl": "pkg:deb/ubuntu/curl@7.68.0-1ubuntu2.25+esm3?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.68.0-1ubuntu2.25+esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "7.65.3-1ubuntu3",
        "7.65.3-1ubuntu4",
        "7.66.0-1ubuntu1",
        "7.67.0-2ubuntu1",
        "7.68.0-1ubuntu1",
        "7.68.0-1ubuntu2",
        "7.68.0-1ubuntu2.1",
        "7.68.0-1ubuntu2.2",
        "7.68.0-1ubuntu2.4",
        "7.68.0-1ubuntu2.5",
        "7.68.0-1ubuntu2.6",
        "7.68.0-1ubuntu2.7",
        "7.68.0-1ubuntu2.10",
        "7.68.0-1ubuntu2.11",
        "7.68.0-1ubuntu2.12",
        "7.68.0-1ubuntu2.13",
        "7.68.0-1ubuntu2.14",
        "7.68.0-1ubuntu2.15",
        "7.68.0-1ubuntu2.16",
        "7.68.0-1ubuntu2.18",
        "7.68.0-1ubuntu2.19",
        "7.68.0-1ubuntu2.20",
        "7.68.0-1ubuntu2.21",
        "7.68.0-1ubuntu2.22",
        "7.68.0-1ubuntu2.23",
        "7.68.0-1ubuntu2.24",
        "7.68.0-1ubuntu2.25",
        "7.68.0-1ubuntu2.25+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "curl",
            "binary_version": "7.81.0-1ubuntu1.23"
          },
          {
            "binary_name": "libcurl3-gnutls",
            "binary_version": "7.81.0-1ubuntu1.23"
          },
          {
            "binary_name": "libcurl3-nss",
            "binary_version": "7.81.0-1ubuntu1.23"
          },
          {
            "binary_name": "libcurl4",
            "binary_version": "7.81.0-1ubuntu1.23"
          }
        ],
        "priority_reason": "Upstream defined it as low"
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "curl",
        "purl": "pkg:deb/ubuntu/curl@7.81.0-1ubuntu1.23?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.81.0-1ubuntu1.23"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "7.74.0-1.3ubuntu2",
        "7.74.0-1.3ubuntu3",
        "7.80.0-3",
        "7.81.0-1",
        "7.81.0-1ubuntu1.1",
        "7.81.0-1ubuntu1.2",
        "7.81.0-1ubuntu1.3",
        "7.81.0-1ubuntu1.4",
        "7.81.0-1ubuntu1.6",
        "7.81.0-1ubuntu1.7",
        "7.81.0-1ubuntu1.8",
        "7.81.0-1ubuntu1.10",
        "7.81.0-1ubuntu1.11",
        "7.81.0-1ubuntu1.13",
        "7.81.0-1ubuntu1.14",
        "7.81.0-1ubuntu1.15",
        "7.81.0-1ubuntu1.16",
        "7.81.0-1ubuntu1.17",
        "7.81.0-1ubuntu1.18",
        "7.81.0-1ubuntu1.19",
        "7.81.0-1ubuntu1.20",
        "7.81.0-1ubuntu1.21",
        "7.81.0-1ubuntu1.22"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "curl",
            "binary_version": "8.5.0-2ubuntu10.8"
          },
          {
            "binary_name": "libcurl3t64-gnutls",
            "binary_version": "8.5.0-2ubuntu10.8"
          },
          {
            "binary_name": "libcurl4t64",
            "binary_version": "8.5.0-2ubuntu10.8"
          }
        ],
        "priority_reason": "Upstream defined it as low"
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "curl",
        "purl": "pkg:deb/ubuntu/curl@8.5.0-2ubuntu10.8?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.5.0-2ubuntu10.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "8.2.1-1ubuntu3",
        "8.2.1-1ubuntu3.1",
        "8.4.0-2ubuntu1",
        "8.5.0-2ubuntu1",
        "8.5.0-2ubuntu2",
        "8.5.0-2ubuntu8",
        "8.5.0-2ubuntu9",
        "8.5.0-2ubuntu10",
        "8.5.0-2ubuntu10.1",
        "8.5.0-2ubuntu10.2",
        "8.5.0-2ubuntu10.3",
        "8.5.0-2ubuntu10.4",
        "8.5.0-2ubuntu10.5",
        "8.5.0-2ubuntu10.6",
        "8.5.0-2ubuntu10.7"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "curl",
            "binary_version": "8.14.1-2ubuntu1.2"
          },
          {
            "binary_name": "libcurl3t64-gnutls",
            "binary_version": "8.14.1-2ubuntu1.2"
          },
          {
            "binary_name": "libcurl4t64",
            "binary_version": "8.14.1-2ubuntu1.2"
          }
        ],
        "priority_reason": "Upstream defined it as low"
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "curl",
        "purl": "pkg:deb/ubuntu/curl@8.14.1-2ubuntu1.2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.14.1-2ubuntu1.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "8.12.1-3ubuntu1",
        "8.13.0-5ubuntu1",
        "8.14.1-1ubuntu2",
        "8.14.1-1ubuntu3",
        "8.14.1-2ubuntu1",
        "8.14.1-2ubuntu1.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "curl",
            "binary_version": "8.18.0-1ubuntu2"
          },
          {
            "binary_name": "libcurl3t64-gnutls",
            "binary_version": "8.18.0-1ubuntu2"
          },
          {
            "binary_name": "libcurl4t64",
            "binary_version": "8.18.0-1ubuntu2"
          }
        ],
        "priority_reason": "Upstream defined it as low"
      },
      "package": {
        "ecosystem": "Ubuntu:26.10",
        "name": "curl",
        "purl": "pkg:deb/ubuntu/curl@8.18.0-1ubuntu2?arch=source\u0026distro=stonking"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.18.0-1ubuntu2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": []
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "curl",
            "binary_version": "8.18.0-1ubuntu2"
          },
          {
            "binary_name": "libcurl3t64-gnutls",
            "binary_version": "8.18.0-1ubuntu2"
          },
          {
            "binary_name": "libcurl4t64",
            "binary_version": "8.18.0-1ubuntu2"
          }
        ],
        "priority_reason": "Upstream defined it as low"
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "curl",
        "purl": "pkg:deb/ubuntu/curl@8.18.0-1ubuntu2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.18.0-1ubuntu2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "8.14.1-2ubuntu1",
        "8.17.0-1ubuntu1",
        "8.18.0-1ubuntu1"
      ]
    }
  ],
  "aliases": [],
  "details": "curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP proxy. The proper behavior is to create or use a separate connection.",
  "id": "UBUNTU-CVE-2026-3784",
  "modified": "2026-10-17T09:37:49Z",
  "published": "2026-03-11T18:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-3784"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-3784"
    },
    {
      "type": "REPORT",
      "url": "https://curl.se/docs/CVE-2026-3784.html"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8084-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8099-1"
    }
  ],
  "related": [
    "USN-8084-1",
    "USN-8099-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "low",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-3784"
  ]
}



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