ubuntu-cve-2026-69249
Vulnerability from osv_ubuntu
Published
2026-08-04 00:00
Modified
2026-08-04 00:00
Summary
Details

python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 49.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.

Severity
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": "python-cryptography",
            "binary_version": "1.2.3-1ubuntu0.3+esm3"
          },
          {
            "binary_name": "python3-cryptography",
            "binary_version": "1.2.3-1ubuntu0.3+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "python-cryptography",
        "purl": "pkg:deb/ubuntu/python-cryptography@1.2.3-1ubuntu0.3+esm3?arch=source\u0026distro=esm-infra/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0.1-1ubuntu1",
        "1.0.2-1",
        "1.1-1",
        "1.1.1-1",
        "1.1.1-1ubuntu1",
        "1.1.1-1ubuntu2",
        "1.1.1-1ubuntu3",
        "1.2.2-2",
        "1.2.3-1",
        "1.2.3-1ubuntu0.1",
        "1.2.3-1ubuntu0.2",
        "1.2.3-1ubuntu0.3",
        "1.2.3-1ubuntu0.3+esm1",
        "1.2.3-1ubuntu0.3+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python-cryptography",
            "binary_version": "2.1.4-1ubuntu1.4+esm3"
          },
          {
            "binary_name": "python3-cryptography",
            "binary_version": "2.1.4-1ubuntu1.4+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "python-cryptography",
        "purl": "pkg:deb/ubuntu/python-cryptography@2.1.4-1ubuntu1.4+esm3?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.9-1",
        "2.1.3-3",
        "2.1.4-1",
        "2.1.4-1build1",
        "2.1.4-1build2",
        "2.1.4-1ubuntu1",
        "2.1.4-1ubuntu1.1",
        "2.1.4-1ubuntu1.2",
        "2.1.4-1ubuntu1.3",
        "2.1.4-1ubuntu1.4",
        "2.1.4-1ubuntu1.4+esm1",
        "2.1.4-1ubuntu1.4+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python-cryptography",
            "binary_version": "2.8-3ubuntu0.3+esm2"
          },
          {
            "binary_name": "python3-cryptography",
            "binary_version": "2.8-3ubuntu0.3+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "python-cryptography",
        "purl": "pkg:deb/ubuntu/python-cryptography@2.8-3ubuntu0.3+esm2?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.6.1-3.1",
        "2.6.1-4",
        "2.6.1-4ubuntu1",
        "2.8-1ubuntu2",
        "2.8-2",
        "2.8-3",
        "2.8-3ubuntu0.1",
        "2.8-3ubuntu0.2",
        "2.8-3ubuntu0.3",
        "2.8-3ubuntu0.3+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-cryptography",
            "binary_version": "3.4.8-1ubuntu2.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "python-cryptography",
        "purl": "pkg:deb/ubuntu/python-cryptography@3.4.8-1ubuntu2.4?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.3.2-1",
        "3.3.2-1build1",
        "3.4.8-1",
        "3.4.8-1ubuntu1",
        "3.4.8-1ubuntu2",
        "3.4.8-1ubuntu2.1",
        "3.4.8-1ubuntu2.2",
        "3.4.8-1ubuntu2.3",
        "3.4.8-1ubuntu2.4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-cryptography",
            "binary_version": "41.0.7-4ubuntu0.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "python-cryptography",
        "purl": "pkg:deb/ubuntu/python-cryptography@41.0.7-4ubuntu0.4?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "38.0.4-4",
        "38.0.4-4ubuntu1",
        "41.0.7-3",
        "41.0.7-4build2",
        "41.0.7-4build3",
        "41.0.7-4ubuntu0.1",
        "41.0.7-4ubuntu0.3",
        "41.0.7-4ubuntu0.4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-cryptography",
            "binary_version": "46.0.5-1ubuntu2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "python-cryptography",
        "purl": "pkg:deb/ubuntu/python-cryptography@46.0.5-1ubuntu2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "43.0.0-1ubuntu1",
        "46.0.1-1ubuntu2",
        "46.0.5-1ubuntu1",
        "46.0.5-1ubuntu2"
      ]
    }
  ],
  "aliases": [],
  "details": "python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 49.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.",
  "id": "UBUNTU-CVE-2026-69249",
  "modified": "2026-08-04T00:00:00Z",
  "published": "2026-08-04T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-69249"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-69249"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-jwv3-5hgf-82ww"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pyca/cryptography/pull/14960"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pyca/cryptography/commit/4a12cf49675a184e47f912b00b04f3a629283582"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "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-2026-69249"
  ]
}



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