Linux Distros Unpatched Vulnerability : CVE-2026-78661

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

include('compat.inc');

if (description)
{
  script_id(373000);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/28");

  script_cve_id("CVE-2026-78661");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-78661");

  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 coalescing adjacent text nodes in addText and fosterParent, appending to an existing TextNode's Data
    via string concatenation (n.Data += text) reallocated and copied the accumulated string on every token.
    Inputs containing many short text runs separated by ignored end tags (such as a</x>) caused O(n^2)
    allocations and byte copies. Accumulate coalesced text in per-node byte slices during parsing and
    materialize Data strings once at the end of parse. (CVE-2026-78661)

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-2026-78661");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-78661");
  script_set_attribute(attribute:"solution", value:
"There is no known solution at this time.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_attribute(attribute:"risk_factor", value:"Medium");

  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:"2026/10/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/28");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04:-:lts");
  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:26.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:26.10");
  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:"cpe:/o:debian:debian_linux:14.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:adsys");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:containerd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.13");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.14");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.16");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.17");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.18");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.20");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.21");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.22");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.23");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.24");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.25");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.26");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.27");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.6");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.8");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-1.9");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-golang-x-net");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:golang-golang-x-net-dev");
  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:google-osconfig-agent");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:juju-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:lxd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:golang-golang-x-net");
  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-12", "Host/OS/Debian Linux-13", "Host/OS/Debian Linux-14", "Host/OS/Ubuntu Linux-14.04", "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-26.04", "Host/OS/Ubuntu Linux-26.10");

  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-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "golang-golang-x-net-dev"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "golang-golang-x-net-dev"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "golang-golang-x-net-dev"}
        ]
      }
    ]
  },
  "Ubuntu Linux-14.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14.04",
        "pkgs": [
          {"reference": "golang-1.10"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "containerd"},
          {"reference": "golang-1.10"},
          {"reference": "golang-1.13"},
          {"reference": "golang-1.18"},
          {"reference": "golang-1.6"},
          {"reference": "golang-1.6-doc"},
          {"reference": "golang-1.6-go"},
          {"reference": "golang-1.6-src"},
          {"reference": "golang-github-lxc-lxd-dev"},
          {"reference": "golang-go.net-dev"},
          {"reference": "golang-golang-x-net-dev"},
          {"reference": "google-guest-agent"},
          {"reference": "google-osconfig-agent"},
          {"reference": "juju"},
          {"reference": "juju-2.0"},
          {"reference": "lxc2"},
          {"reference": "lxd"},
          {"reference": "lxd-client"},
          {"reference": "lxd-tools"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "containerd"},
          {"reference": "golang-1.10"},
          {"reference": "golang-1.10-doc"},
          {"reference": "golang-1.10-go"},
          {"reference": "golang-1.10-src"},
          {"reference": "golang-1.13"},
          {"reference": "golang-1.16"},
          {"reference": "golang-1.18"},
          {"reference": "golang-1.8"},
          {"reference": "golang-1.9"},
          {"reference": "golang-golang-x-net-dev"},
          {"reference": "google-guest-agent"},
          {"reference": "google-osconfig-agent"},
          {"reference": "lxd"},
          {"reference": "lxd-client"},
          {"reference": "lxd-tools"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "adsys"},
          {"reference": "containerd"},
          {"reference": "golang-1.13"},
          {"reference": "golang-1.13-doc"},
          {"reference": "golang-1.13-go"},
          {"reference": "golang-1.13-src"},
          {"reference": "golang-1.14"},
          {"reference": "golang-1.14-doc"},
          {"reference": "golang-1.14-go"},
          {"reference": "golang-1.14-src"},
          {"reference": "golang-1.16"},
          {"reference": "golang-1.18"},
          {"reference": "golang-1.20"},
          {"reference": "golang-1.21"},
          {"reference": "golang-1.22"},
          {"reference": "golang-github-docker-containerd-dev"},
          {"reference": "golang-golang-x-net-dev"},
          {"reference": "google-guest-agent"},
          {"reference": "google-osconfig-agent"},
          {"reference": "lxd"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "adsys"},
          {"reference": "containerd"},
          {"reference": "golang-1.13"},
          {"reference": "golang-1.17"},
          {"reference": "golang-1.17-doc"},
          {"reference": "golang-1.17-go"},
          {"reference": "golang-1.17-src"},
          {"reference": "golang-1.18"},
          {"reference": "golang-1.18-doc"},
          {"reference": "golang-1.18-go"},
          {"reference": "golang-1.18-src"},
          {"reference": "golang-1.20"},
          {"reference": "golang-1.21"},
          {"reference": "golang-1.22"},
          {"reference": "golang-1.23"},
          {"reference": "golang-1.24"},
          {"reference": "golang-1.25"},
          {"reference": "golang-1.26"},
          {"reference": "golang-github-containerd-containerd-dev"},
          {"reference": "golang-golang-x-net"},
          {"reference": "google-guest-agent"},
          {"reference": "google-osconfig-agent"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "adsys"},
          {"reference": "adsys-windows"},
          {"reference": "containerd"},
          {"reference": "golang-1.21"},
          {"reference": "golang-1.22"},
          {"reference": "golang-1.22-doc"},
          {"reference": "golang-1.22-go"},
          {"reference": "golang-1.22-src"},
          {"reference": "golang-1.23"},
          {"reference": "golang-1.24"},
          {"reference": "golang-1.25"},
          {"reference": "golang-1.26"},
          {"reference": "golang-golang-x-net"},
          {"reference": "google-guest-agent"},
          {"reference": "google-osconfig-agent"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.10": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.10",
        "pkgs": [
          {"reference": "adsys"},
          {"reference": "adsys-windows"},
          {"reference": "containerd"},
          {"reference": "golang-1.26"},
          {"reference": "golang-1.27"},
          {"reference": "golang-1.27-doc"},
          {"reference": "golang-1.27-go"},
          {"reference": "golang-1.27-src"},
          {"reference": "golang-golang-x-net"},
          {"reference": "google-guest-agent"},
          {"reference": "google-osconfig-agent"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "adsys"},
          {"reference": "adsys-windows"},
          {"reference": "containerd"},
          {"reference": "golang-1.23"},
          {"reference": "golang-1.24"},
          {"reference": "golang-1.24-doc"},
          {"reference": "golang-1.24-go"},
          {"reference": "golang-1.24-src"},
          {"reference": "golang-1.25"},
          {"reference": "golang-1.25-doc"},
          {"reference": "golang-1.25-go"},
          {"reference": "golang-1.25-src"},
          {"reference": "golang-1.26"},
          {"reference": "golang-1.26-doc"},
          {"reference": "golang-1.26-go"},
          {"reference": "golang-1.26-src"},
          {"reference": "golang-golang-x-net"},
          {"reference": "google-guest-agent"},
          {"reference": "google-osconfig-agent"}
        ]
      }
    ]
  }
};

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 third_party_support = get_kb_item('Host/OS/extended-third-party');
if (!empty_or_null(third_party_support)) {
    var third_party_vendors = distro_constraints_values['third_party'];
    if (!empty_or_null(third_party_vendors)) {
        var vendor;
        foreach vendor (third_party_vendors) {
            if (vendor == third_party_support) exit(0, 'A third party management patch is available for this vulnerability from ' + vendor + '.\n');
        }
    }
}

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');
}