USN-8539-1 (UBUNTU-CVE-2026-42011)

Vulnerability from osv_ubuntu – Published: 2026-07-14 15:16 – Updated: 2026-07-14 15:16 – Source website
VLAI
Summary
gnutls28 vulnerabilities
Details

Haruto Kimura discovered that GnuTLS did not properly apply permitted name constraints in certain certificate validation paths. A remote attacker could possibly use this issue to bypass certificate validation, leading to a machine-in-the-middle attack. (CVE-2026-42011)

Oleh Konko discovered that GnuTLS incorrectly fell back to Common Name checks for certain URI and SRV subject alternative names. A remote attacker could possibly use this issue to bypass certificate validation, leading to a machine-in-the-middle attack. (CVE-2026-42012)

Haruto Kimura and Joshua Rogers discovered that GnuTLS incorrectly fell back to Common Name checks when subject alternative names were oversized. A remote attacker could possibly use this issue to bypass certificate validation, leading to a machine-in-the-middle attack. (CVE-2026-42013)

Luigino Camastra and Joshua Rogers discovered that GnuTLS had a use-after-free issue when changing PKCS#11 token security officer PINs in certain cases. An attacker could possibly use this issue to cause GnuTLS to crash, resulting in a denial of service, or execute arbitrary code. (CVE-2026-42014)

Zou Dikai discovered that GnuTLS did not properly validate PKCS#12 bag sizes in certain cases. An attacker could possibly use this issue to cause GnuTLS to crash, resulting in a denial of service, or execute arbitrary code. (CVE-2026-42015)

References
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{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-42012",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-42013",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-42015",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:Pro:16.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "gnutls-bin",
            "binary_version": "3.4.10-4ubuntu1.9+esm4"
          },
          {
            "binary_name": "guile-gnutls",
            "binary_version": "3.4.10-4ubuntu1.9+esm4"
          },
          {
            "binary_name": "libgnutls-openssl27",
            "binary_version": "3.4.10-4ubuntu1.9+esm4"
          },
          {
            "binary_name": "libgnutls30",
            "binary_version": "3.4.10-4ubuntu1.9+esm4"
          },
          {
            "binary_name": "libgnutlsxx28",
            "binary_version": "3.4.10-4ubuntu1.9+esm4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "gnutls28",
        "purl": "pkg:deb/ubuntu/gnutls28@3.4.10-4ubuntu1.9+esm4?arch=source\u0026distro=esm-infra-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.4.10-4ubuntu1.9+esm4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.3.15-5ubuntu2",
        "3.3.18-1ubuntu1",
        "3.3.20-1ubuntu1",
        "3.4.9-2ubuntu1",
        "3.4.10-4ubuntu1",
        "3.4.10-4ubuntu1.1",
        "3.4.10-4ubuntu1.2",
        "3.4.10-4ubuntu1.3",
        "3.4.10-4ubuntu1.4",
        "3.4.10-4ubuntu1.5",
        "3.4.10-4ubuntu1.6",
        "3.4.10-4ubuntu1.7",
        "3.4.10-4ubuntu1.8",
        "3.4.10-4ubuntu1.9",
        "3.4.10-4ubuntu1.9+esm1",
        "3.4.10-4ubuntu1.9+esm2",
        "3.4.10-4ubuntu1.9+esm3"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-42011",
              "severity": [
                {
                  "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"
                }
              ]
            },
            {
              "id": "CVE-2026-42012",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-42013",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-42015",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
                  "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": "gnutls-bin",
            "binary_version": "3.5.18-1ubuntu1.6+esm4"
          },
          {
            "binary_name": "libgnutls-dane0",
            "binary_version": "3.5.18-1ubuntu1.6+esm4"
          },
          {
            "binary_name": "libgnutls-openssl27",
            "binary_version": "3.5.18-1ubuntu1.6+esm4"
          },
          {
            "binary_name": "libgnutls30",
            "binary_version": "3.5.18-1ubuntu1.6+esm4"
          },
          {
            "binary_name": "libgnutlsxx28",
            "binary_version": "3.5.18-1ubuntu1.6+esm4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "gnutls28",
        "purl": "pkg:deb/ubuntu/gnutls28@3.5.18-1ubuntu1.6+esm4?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.5.18-1ubuntu1.6+esm4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.5.8-6ubuntu3",
        "3.5.17-1ubuntu1",
        "3.5.17-1ubuntu3",
        "3.5.18-1ubuntu1",
        "3.5.18-1ubuntu1.1",
        "3.5.18-1ubuntu1.2",
        "3.5.18-1ubuntu1.3",
        "3.5.18-1ubuntu1.4",
        "3.5.18-1ubuntu1.5",
        "3.5.18-1ubuntu1.6",
        "3.5.18-1ubuntu1.6+esm1",
        "3.5.18-1ubuntu1.6+esm2",
        "3.5.18-1ubuntu1.6+esm3"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-42011",
              "severity": [
                {
                  "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"
                }
              ]
            },
            {
              "id": "CVE-2026-42012",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-42013",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-42014",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-42015",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
                  "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": "gnutls-bin",
            "binary_version": "3.6.13-2ubuntu1.12+esm3"
          },
          {
            "binary_name": "guile-gnutls",
            "binary_version": "3.6.13-2ubuntu1.12+esm3"
          },
          {
            "binary_name": "libgnutls-dane0",
            "binary_version": "3.6.13-2ubuntu1.12+esm3"
          },
          {
            "binary_name": "libgnutls-openssl27",
            "binary_version": "3.6.13-2ubuntu1.12+esm3"
          },
          {
            "binary_name": "libgnutls30",
            "binary_version": "3.6.13-2ubuntu1.12+esm3"
          },
          {
            "binary_name": "libgnutlsxx28",
            "binary_version": "3.6.13-2ubuntu1.12+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "gnutls28",
        "purl": "pkg:deb/ubuntu/gnutls28@3.6.13-2ubuntu1.12+esm3?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.6.13-2ubuntu1.12+esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.6.9-5ubuntu1",
        "3.6.9-5ubuntu2",
        "3.6.10-5",
        "3.6.11.1-2",
        "3.6.11.1-2ubuntu2",
        "3.6.13-2ubuntu1",
        "3.6.13-2ubuntu1.1",
        "3.6.13-2ubuntu1.2",
        "3.6.13-2ubuntu1.3",
        "3.6.13-2ubuntu1.6",
        "3.6.13-2ubuntu1.7",
        "3.6.13-2ubuntu1.8",
        "3.6.13-2ubuntu1.9",
        "3.6.13-2ubuntu1.10",
        "3.6.13-2ubuntu1.11",
        "3.6.13-2ubuntu1.12",
        "3.6.13-2ubuntu1.12+esm1",
        "3.6.13-2ubuntu1.12+esm2"
      ]
    }
  ],
  "aliases": [],
  "details": "Haruto Kimura discovered that GnuTLS did not properly apply permitted\nname constraints in certain certificate validation paths. A remote\nattacker could possibly use this issue to bypass certificate validation,\nleading to a machine-in-the-middle attack. (CVE-2026-42011)\n\nOleh Konko discovered that GnuTLS incorrectly fell back to Common Name\nchecks for certain URI and SRV subject alternative names. A remote\nattacker could possibly use this issue to bypass certificate validation,\nleading to a machine-in-the-middle attack. (CVE-2026-42012)\n\nHaruto Kimura and Joshua Rogers discovered that GnuTLS incorrectly fell\nback to Common Name checks when subject alternative names were\noversized. A remote attacker could possibly use this issue to bypass\ncertificate validation, leading to a machine-in-the-middle attack.\n(CVE-2026-42013)\n\nLuigino Camastra and Joshua Rogers discovered that GnuTLS had a\nuse-after-free issue when changing PKCS#11 token security officer PINs\nin certain cases. An attacker could possibly use this issue to cause\nGnuTLS to crash, resulting in a denial of service, or execute arbitrary\ncode. (CVE-2026-42014)\n\nZou Dikai discovered that GnuTLS did not properly validate PKCS#12 bag\nsizes in certain cases. An attacker could possibly use this issue to\ncause GnuTLS to crash, resulting in a denial of service, or execute\narbitrary code. (CVE-2026-42015)",
  "id": "USN-8539-1",
  "modified": "2026-07-14T15:16:35Z",
  "published": "2026-07-14T15:16:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8539-1"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-42011"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-42012"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-42013"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-42014"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-42015"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "gnutls28 vulnerabilities",
  "upstream": [
    "UBUNTU-CVE-2026-42011",
    "UBUNTU-CVE-2026-42012",
    "UBUNTU-CVE-2026-42013",
    "UBUNTU-CVE-2026-42014",
    "UBUNTU-CVE-2026-42015"
  ]
}



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