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USN-8540-1 (UBUNTU-CVE-2026-11771)

Vulnerability from osv_ubuntu – Published: 2026-07-14 15:40 – Updated: 2026-08-06 19:28 – Source website
VLAI
Summary
openvpn vulnerabilities
Details

It was discovered that OpenVPN had a 1-byte buffer overrun when handling NTLMv2 proxy responses. An attacker could use this issue to cause a denial of service or possibly execute arbitrary code. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-11771)

It was discovered that OpenVPN incorrectly handled metadata when extracting tls-crypt-v2 client keys. An attacker could possibly use this issue to obtain sensitive information. (CVE-2026-12932)

It was discovered that OpenVPN had a use-after-free in the ack_write_buf handling. An attacker could use this issue to cause OpenVPN to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-12996)

It was discovered that OpenVPN had a use-after-free in the tls_wrap_reneg handling. An attacker could use this issue to cause OpenVPN to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-13117)

It was discovered that OpenVPN incorrectly validated authentication tokens when external authentication was enabled. A remote attacker could possibly use this issue to cause OpenVPN to crash, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-13122)

It was discovered that OpenVPN had a memory leak when handling tls-crypt-v2 client keys. A remote attacker with a valid tls-crypt-v2 client key could possibly use this issue to cause OpenVPN to consume excessive resources, leading to a denial of service. (CVE-2026-13698)

References
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-12932",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-12996",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-13698",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:22.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "openvpn",
            "binary_version": "2.5.11-0ubuntu0.22.04.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "openvpn",
        "purl": "pkg:deb/ubuntu/openvpn@2.5.11-0ubuntu0.22.04.4?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.5.11-0ubuntu0.22.04.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.5.1-3ubuntu1",
        "2.5.1-3ubuntu2",
        "2.5.1-3ubuntu4",
        "2.5.1-3ubuntu5",
        "2.5.5-1ubuntu1",
        "2.5.5-1ubuntu3",
        "2.5.5-1ubuntu3.1",
        "2.5.9-0ubuntu0.22.04.2",
        "2.5.9-0ubuntu0.22.04.3",
        "2.5.11-0ubuntu0.22.04.1",
        "2.5.11-0ubuntu0.22.04.3"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-11771",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-12932",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-12996",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-13117",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-13122",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-13698",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:24.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "openvpn",
            "binary_version": "2.6.19-0ubuntu0.24.04.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "openvpn",
        "purl": "pkg:deb/ubuntu/openvpn@2.6.19-0ubuntu0.24.04.3?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.6.19-0ubuntu0.24.04.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.6.5-0ubuntu1",
        "2.6.7-1ubuntu1",
        "2.6.9-1ubuntu2",
        "2.6.9-1ubuntu3",
        "2.6.9-1ubuntu4",
        "2.6.9-1ubuntu4.1",
        "2.6.12-0ubuntu0.24.04.1",
        "2.6.12-0ubuntu0.24.04.3",
        "2.6.14-0ubuntu0.24.04.1",
        "2.6.14-0ubuntu0.24.04.2",
        "2.6.14-0ubuntu0.24.04.3",
        "2.6.19-0ubuntu0.24.04.1",
        "2.6.19-0ubuntu0.24.04.2"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-11771",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-12932",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-12996",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-13117",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-13122",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-13698",
              "severity": [
                {
                  "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
                  "type": "CVSS_V4"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:26.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "openvpn",
            "binary_version": "2.7.0-1ubuntu1.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "openvpn",
        "purl": "pkg:deb/ubuntu/openvpn@2.7.0-1ubuntu1.2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.7.0-1ubuntu1.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.6.14-2ubuntu1",
        "2.6.15-1ubuntu1",
        "2.7.0~rc5-1ubuntu5",
        "2.7.0~rc6-1ubuntu1",
        "2.7.0-1ubuntu1",
        "2.7.0-1ubuntu1.1"
      ]
    }
  ],
  "aliases": [],
  "details": "It was discovered that OpenVPN had a 1-byte buffer overrun when handling\nNTLMv2 proxy responses. An attacker could use this issue to cause a denial\nof service or possibly execute arbitrary code. This issue only affected\nUbuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-11771)\n\nIt was discovered that OpenVPN incorrectly handled metadata when extracting\ntls-crypt-v2 client keys. An attacker could possibly use this issue to\nobtain sensitive information. (CVE-2026-12932)\n\nIt was discovered that OpenVPN had a use-after-free in the ack_write_buf\nhandling. An attacker could use this issue to cause OpenVPN to crash,\nresulting in a denial of service, or possibly execute arbitrary code.\n(CVE-2026-12996)\n\nIt was discovered that OpenVPN had a use-after-free in the tls_wrap_reneg\nhandling. An attacker could use this issue to cause OpenVPN to crash,\nresulting in a denial of service, or possibly execute arbitrary code. This\nissue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-13117)\n\nIt was discovered that OpenVPN incorrectly validated authentication tokens\nwhen external authentication was enabled. A remote attacker could possibly\nuse this issue to cause OpenVPN to crash, resulting in a denial of service.\nThis issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS.\n(CVE-2026-13122)\n\nIt was discovered that OpenVPN had a memory leak when handling tls-crypt-v2\nclient keys. A remote attacker with a valid tls-crypt-v2 client key could\npossibly use this issue to cause OpenVPN to consume excessive resources,\nleading to a denial of service. (CVE-2026-13698)",
  "id": "USN-8540-1",
  "modified": "2026-08-06T19:28:31Z",
  "published": "2026-07-14T15:40:18Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8540-1"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-11771"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-12932"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-12996"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-13117"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-13122"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-13698"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "openvpn vulnerabilities",
  "upstream": [
    "UBUNTU-CVE-2026-11771",
    "UBUNTU-CVE-2026-12932",
    "UBUNTU-CVE-2026-12996",
    "UBUNTU-CVE-2026-13117",
    "UBUNTU-CVE-2026-13122",
    "UBUNTU-CVE-2026-13698"
  ]
}



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