Linux Distros Unpatched Vulnerability : CVE-2026-39832

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(316565);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/05/30");

  script_cve_id("CVE-2026-39832");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-39832");

  script_set_attribute(attribute:"synopsis", value:
"The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be
patched.");
  script_set_attribute(attribute:"description", value:
"The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied
patch available.

  - When adding a key to a remote agent constraint extensions such as [email protected]
    were not serialized in the request. Destination restrictions were silently stripped when forwarding keys,
    allowing unrestricted use of the key on the remote host. The client now serializes all constraint
    extensions. Additionally, the in-memory keyring returned by NewKeyring() now rejects keys with unsupported
    constraint extensions instead of silently ignoring them. (CVE-2026-39832)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-39832");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-39832");
  script_set_attribute(attribute:"solution", value:
"There is no known solution at this time.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-39832");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_set_attribute(attribute:"vendor_unpatched", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/05/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/05/25");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:22.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:24.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:25.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:26.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:12.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:13.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-go.crypto");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:google-guest-agent");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:lxd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:snapd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:golang-go.crypto");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl", "set_linux_os_id.nasl");
  script_require_keys("Host/cpu", "Host/local_checks_enabled", "global_settings/vendor_unpatched", "Host/OS/identifier");
  script_require_ports("Host/OS/Debian Linux-11", "Host/OS/Debian Linux-12", "Host/OS/Debian Linux-13", "Host/OS/Ubuntu Linux-16.04", "Host/OS/Ubuntu Linux-18.04", "Host/OS/Ubuntu Linux-20.04", "Host/OS/Ubuntu Linux-22.04", "Host/OS/Ubuntu Linux-24.04", "Host/OS/Ubuntu Linux-25.10", "Host/OS/Ubuntu Linux-26.04");

  exit(0);
}

if (!get_kb_item("global_settings/vendor_unpatched")) exit(0, "Unpatched Vulnerabilities Detection not active.");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (empty_or_null(get_one_kb_item("Host/Debian/dpkg-l"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Debian Linux-11": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "11",
        "pkgs": [
          {"reference": "golang-golang-x-crypto-dev"}
        ]
      }
    ]
  },
  "Debian Linux-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "golang-golang-x-crypto-dev"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "golang-golang-x-crypto-dev"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "golang-github-lxc-lxd-dev"},
          {"reference": "golang-github-ubuntu-core-snappy-dev"},
          {"reference": "golang-go.crypto-dev"},
          {"reference": "golang-golang-x-crypto-dev"},
          {"reference": "google-guest-agent"},
          {"reference": "lxc2"},
          {"reference": "lxd"},
          {"reference": "lxd-client"},
          {"reference": "lxd-tools"},
          {"reference": "snapd"},
          {"reference": "ubuntu-core-snapd-units"},
          {"reference": "ubuntu-snappy"},
          {"reference": "ubuntu-snappy-cli"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "golang-github-snapcore-snapd-dev"},
          {"reference": "golang-github-ubuntu-core-snappy-dev"},
          {"reference": "golang-go.crypto"},
          {"reference": "google-guest-agent"},
          {"reference": "lxd"},
          {"reference": "lxd-client"},
          {"reference": "lxd-tools"},
          {"reference": "snap-confine"},
          {"reference": "snapd"},
          {"reference": "snapd-xdg-open"},
          {"reference": "ubuntu-core-launcher"},
          {"reference": "ubuntu-core-snapd-units"},
          {"reference": "ubuntu-snappy"},
          {"reference": "ubuntu-snappy-cli"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "golang-github-snapcore-snapd-dev"},
          {"reference": "golang-github-ubuntu-core-snappy-dev"},
          {"reference": "golang-go.crypto"},
          {"reference": "google-guest-agent"},
          {"reference": "snap-confine"},
          {"reference": "snapd"},
          {"reference": "snapd-xdg-open"},
          {"reference": "ubuntu-core-launcher"},
          {"reference": "ubuntu-core-snapd-units"},
          {"reference": "ubuntu-snappy"},
          {"reference": "ubuntu-snappy-cli"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "golang-github-snapcore-snapd-dev"},
          {"reference": "golang-github-ubuntu-core-snappy-dev"},
          {"reference": "golang-go.crypto"},
          {"reference": "google-guest-agent"},
          {"reference": "snap-confine"},
          {"reference": "snapd"},
          {"reference": "snapd-xdg-open"},
          {"reference": "ubuntu-core-launcher"},
          {"reference": "ubuntu-core-snapd-units"},
          {"reference": "ubuntu-snappy"},
          {"reference": "ubuntu-snappy-cli"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "golang-github-snapcore-snapd-dev"},
          {"reference": "golang-github-ubuntu-core-snappy-dev"},
          {"reference": "golang-go.crypto"},
          {"reference": "google-guest-agent"},
          {"reference": "snap-confine"},
          {"reference": "snapd"},
          {"reference": "snapd-xdg-open"},
          {"reference": "ubuntu-core-launcher"},
          {"reference": "ubuntu-core-snapd-units"},
          {"reference": "ubuntu-snappy"},
          {"reference": "ubuntu-snappy-cli"}
        ]
      }
    ]
  },
  "Ubuntu Linux-25.10": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "25.10",
        "pkgs": [
          {"reference": "golang-github-snapcore-snapd-dev"},
          {"reference": "golang-github-ubuntu-core-snappy-dev"},
          {"reference": "golang-go.crypto"},
          {"reference": "google-guest-agent"},
          {"reference": "snap-confine"},
          {"reference": "snapd"},
          {"reference": "snapd-xdg-open"},
          {"reference": "ubuntu-core-launcher"},
          {"reference": "ubuntu-core-snapd-units"},
          {"reference": "ubuntu-snappy"},
          {"reference": "ubuntu-snappy-cli"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "golang-github-snapcore-snapd-dev"},
          {"reference": "golang-go.crypto"},
          {"reference": "google-guest-agent"},
          {"reference": "snapd"}
        ]
      }
    ]
  }
};

var distro_constraints_values = linux_unpatched::get_distro_constraints(distro_constraints_arr:distro_constraints_array);
if (empty_or_null(distro_constraints_values)) audit(AUDIT_HOST_NOT, 'affected');
var report = linux_unpatched::check_unpatched_constraints(distro_constraints_values:distro_constraints_values);

if (!empty_or_null(report))
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}