Vulnerability-Lookup

usn-8087-3

Vulnerability from osv_ubuntu

Published

2026-04-28 11:04

Modified

2026-07-20 13:46

Summary

python-cryptography vulnerability

Details

USN-8087-1 fixed a vulnerability in python-cryptography. This update provides the corresponding update to Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS.

Original advisory details:

It was discovered that python-cryptography incorrectly handled subgroup validation for SECT curves. A remote attacker could use this issue to perform a subgroup attack and possibly recover the least significant bits of private keys.

References

URL

Type

	https://ubuntu.com/security/notices/USN-8087-3	ADVISORY
	https://ubuntu.com/security/CVE-2026-26007	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-26007",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:Pro:16.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "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"
            },
            {
              "fixed": "1.2.3-1ubuntu0.3+esm3"
            }
          ],
          "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"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-26007",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:Pro:18.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "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"
            },
            {
              "fixed": "2.1.4-1ubuntu1.4+esm3"
            }
          ],
          "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"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-26007",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:Pro:20.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "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"
            },
            {
              "fixed": "2.8-3ubuntu0.3+esm2"
            }
          ],
          "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"
      ]
    }
  ],
  "aliases": [],
  "details": "USN-8087-1 fixed a vulnerability in python-cryptography. This update\nprovides the corresponding update to Ubuntu 16.04 LTS, Ubuntu 18.04 LTS,\nand Ubuntu 20.04 LTS.\n\nOriginal advisory details:\n\n It was discovered that python-cryptography incorrectly handled subgroup\n validation for SECT curves. A remote attacker could use this issue to\n perform a subgroup attack and possibly recover the least significant bits\n of private keys.",
  "id": "USN-8087-3",
  "modified": "2026-07-20T13:46:31Z",
  "published": "2026-04-28T11:04:02Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8087-3"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-26007"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "python-cryptography vulnerability",
  "upstream": [
    "UBUNTU-CVE-2026-26007"
  ]
}

ubuntu-cve-2026-26007

Vulnerability from osv_ubuntu

Published

2026-02-10 22:17

Modified

2026-07-20 14:11

Summary

Details

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 46.0.5, the public_key_from_numbers (or EllipticCurvePublicNumbers.public_key()), EllipticCurvePublicNumbers.public_key(), load_der_public_key() and load_pem_public_key() functions do not verify that the point belongs to the expected prime-order subgroup of the curve. This missing validation allows an attacker to provide a public key point P from a small-order subgroup. This can lead to security issues in various situations, such as the most commonly used signature verification (ECDSA) and shared key negotiation (ECDH). When the victim computes the shared secret as S = [victim_private_key]P via ECDH, this leaks information about victim_private_key mod (small_subgroup_order). For curves with cofactor > 1, this reveals the least significant bits of the private key. When these weak public keys are used in ECDSA , it's easy to forge signatures on the small subgroup. Only SECT curves are impacted by this. This vulnerability is fixed in 46.0.5.

Severity

8.2 (High)


                    
                      CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

6.5 (Medium)


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

7.4 (High)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-26007	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-26007	REPORT
	https://github.com/pyca/cryptography/security/adv…	REPORT
	http://www.openwall.com/lists/oss-security/2026/02/10/4	REPORT
	https://ubuntu.com/security/notices/USN-8087-1	ADVISORY
	https://ubuntu.com/security/notices/USN-8087-3	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "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"
            },
            {
              "fixed": "1.2.3-1ubuntu0.3+esm3"
            }
          ],
          "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"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "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"
            },
            {
              "fixed": "2.1.4-1ubuntu1.4+esm3"
            }
          ],
          "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"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "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"
            },
            {
              "fixed": "2.8-3ubuntu0.3+esm2"
            }
          ],
          "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"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "python3-cryptography",
            "binary_version": "3.4.8-1ubuntu2.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "python-cryptography",
        "purl": "pkg:deb/ubuntu/python-cryptography@3.4.8-1ubuntu2.3?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.4.8-1ubuntu2.3"
            }
          ],
          "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"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "python3-cryptography",
            "binary_version": "41.0.7-4ubuntu0.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "python-cryptography",
        "purl": "pkg:deb/ubuntu/python-cryptography@41.0.7-4ubuntu0.3?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "41.0.7-4ubuntu0.3"
            }
          ],
          "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"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "python3-cryptography",
            "binary_version": "43.0.0-1ubuntu1.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "python-cryptography",
        "purl": "pkg:deb/ubuntu/python-cryptography@43.0.0-1ubuntu1.1?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "43.0.0-1ubuntu1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "43.0.0-1ubuntu1"
      ]
    }
  ],
  "aliases": [],
  "details": "cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 46.0.5, the public_key_from_numbers (or EllipticCurvePublicNumbers.public_key()), EllipticCurvePublicNumbers.public_key(), load_der_public_key() and load_pem_public_key() functions do not verify that the point belongs to the expected prime-order subgroup of the curve. This missing validation allows an attacker to provide a public key point P from a small-order subgroup. This can lead to security issues in various situations, such as the most commonly used signature verification (ECDSA) and shared key negotiation (ECDH). When the victim computes the shared secret as S = [victim_private_key]P via ECDH, this leaks information about victim_private_key mod (small_subgroup_order). For curves with cofactor \u003e 1, this reveals the least significant bits of the private key. When these weak public keys are used in ECDSA , it\u0027s easy to forge signatures on the small subgroup. Only SECT curves are impacted by this. This vulnerability is fixed in 46.0.5.",
  "id": "UBUNTU-CVE-2026-26007",
  "modified": "2026-07-20T14:11:54Z",
  "published": "2026-02-10T22:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-26007"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-26007"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-r6ph-v2qm-q3c2"
    },
    {
      "type": "REPORT",
      "url": "http://www.openwall.com/lists/oss-security/2026/02/10/4"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8087-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8087-3"
    }
  ],
  "related": [
    "USN-8087-1",
    "USN-8087-3"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-26007"
  ]
}

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.

Detection rules are retrieved from Rulezet.

Action not permitted

usn-8087-3

Vulnerability from osv_ubuntu

ubuntu-cve-2026-26007

Vulnerability from osv_ubuntu

Tags

Sightings

Nomenclature