Linux Distros Unpatched Vulnerability : CVE-2026-16768

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

include('compat.inc');

if (description)
{
  script_id(329398);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/25");

  script_cve_id("CVE-2026-16768");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-16768");

  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.

  - A flaw was found in gdk-pixbuf. When parsing a specially crafted ICO file with pixel values that exceed
    the defined palette range, an out-of-bounds read can occur due to improper bounds checking against the
    actual palette size. This vulnerability causes heap bytes to be interpreted as valid palette indices and
    rendered as RGB pixel values in the output image, allowing an attacker to extract heap content via the
    generated output, such as a thumbnail. (CVE-2026-16768)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2026-16768");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-16768");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-16768");
  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:M/Au:N/C:P/I:N/A:P");
  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:L/I:N/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-2026-16768");

  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:"2026/07/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/07/25");

  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:26.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:8");
  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:"cpe:/o:debian:debian_linux:14.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:6");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:9");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gdk-pixbuf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gdk-pixbuf2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gdk-pixbuf2-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gdk-pixbuf2-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gdk-pixbuf2-tests");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gdk-pixbuf2-xlib");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gdk-pixbuf2-xlib-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:gdk-pixbuf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gdk-pixbuf2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gdk-pixbuf2-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gdk-pixbuf2-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gdk-pixbuf2-tests");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gdk-pixbuf2-xlib");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gdk-pixbuf2-xlib-devel");
  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/CentOS Linux-7", "Host/OS/CentOS Linux-8", "Host/OS/Debian Linux-11", "Host/OS/Debian Linux-12", "Host/OS/Debian Linux-13", "Host/OS/Debian Linux-14", "Host/OS/Red Hat Enterprise Linux-10", "Host/OS/Red Hat Enterprise Linux-6", "Host/OS/Red Hat Enterprise Linux-7", "Host/OS/Red Hat Enterprise Linux-8", "Host/OS/Red Hat Enterprise Linux-9", "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");

  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/CentOS/rpm-list")) && empty_or_null(get_one_kb_item("Host/Debian/dpkg-l")) && empty_or_null(get_one_kb_item("Host/RedHat/rpm-list"))) 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": "gdk-pixbuf-tests"},
          {"reference": "gir1.2-gdkpixbuf-2.0"},
          {"reference": "libgdk-pixbuf-2.0-0"},
          {"reference": "libgdk-pixbuf-2.0-0-udeb"},
          {"reference": "libgdk-pixbuf-2.0-dev"},
          {"reference": "libgdk-pixbuf2.0-0-udeb"},
          {"reference": "libgdk-pixbuf2.0-bin"},
          {"reference": "libgdk-pixbuf2.0-common"},
          {"reference": "libgdk-pixbuf2.0-doc"}
        ]
      }
    ]
  },
  "Debian Linux-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "gdk-pixbuf-tests"},
          {"reference": "gir1.2-gdkpixbuf-2.0"},
          {"reference": "libgdk-pixbuf-2.0-0"},
          {"reference": "libgdk-pixbuf-2.0-0-udeb"},
          {"reference": "libgdk-pixbuf-2.0-dev"},
          {"reference": "libgdk-pixbuf2.0-0-udeb"},
          {"reference": "libgdk-pixbuf2.0-bin"},
          {"reference": "libgdk-pixbuf2.0-common"},
          {"reference": "libgdk-pixbuf2.0-doc"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "gdk-pixbuf-tests"},
          {"reference": "gir1.2-gdkpixbuf-2.0"},
          {"reference": "libgdk-pixbuf-2.0-0"},
          {"reference": "libgdk-pixbuf-2.0-0-udeb"},
          {"reference": "libgdk-pixbuf-2.0-dev"},
          {"reference": "libgdk-pixbuf2.0-0-udeb"},
          {"reference": "libgdk-pixbuf2.0-bin"},
          {"reference": "libgdk-pixbuf2.0-common"},
          {"reference": "libgdk-pixbuf2.0-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "gdk-pixbuf-tests"},
          {"reference": "gir1.2-gdkpixbuf-2.0"},
          {"reference": "libgdk-pixbuf-2.0-0"},
          {"reference": "libgdk-pixbuf-2.0-0-udeb"},
          {"reference": "libgdk-pixbuf-2.0-dev"},
          {"reference": "libgdk-pixbuf2.0-0-udeb"},
          {"reference": "libgdk-pixbuf2.0-bin"},
          {"reference": "libgdk-pixbuf2.0-common"},
          {"reference": "libgdk-pixbuf2.0-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "gdk-pixbuf-tests"},
          {"reference": "gir1.2-gdkpixbuf-2.0"},
          {"reference": "libgdk-pixbuf-2.0-0"},
          {"reference": "libgdk-pixbuf-2.0-0-udeb"},
          {"reference": "libgdk-pixbuf-2.0-dev"},
          {"reference": "libgdk-pixbuf2.0-0-udeb"},
          {"reference": "libgdk-pixbuf2.0-bin"},
          {"reference": "libgdk-pixbuf2.0-common"},
          {"reference": "libgdk-pixbuf2.0-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "gdk-pixbuf-tests"},
          {"reference": "gir1.2-gdkpixbuf-2.0"},
          {"reference": "libgdk-pixbuf-2.0-0"},
          {"reference": "libgdk-pixbuf-2.0-0-udeb"},
          {"reference": "libgdk-pixbuf-2.0-dev"},
          {"reference": "libgdk-pixbuf2.0-0-udeb"},
          {"reference": "libgdk-pixbuf2.0-bin"},
          {"reference": "libgdk-pixbuf2.0-common"},
          {"reference": "libgdk-pixbuf2.0-doc"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "gdk-pixbuf-tests"},
          {"reference": "gir1.2-gdkpixbuf-2.0"},
          {"reference": "libgdk-pixbuf-2.0-0"},
          {"reference": "libgdk-pixbuf-2.0-0-udeb"},
          {"reference": "libgdk-pixbuf-2.0-dev"},
          {"reference": "libgdk-pixbuf2.0-bin"},
          {"reference": "libgdk-pixbuf2.0-common"},
          {"reference": "libgdk-pixbuf2.0-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "gir1.2-gdkpixbuf-2.0"},
          {"reference": "libgdk-pixbuf2.0-0"},
          {"reference": "libgdk-pixbuf2.0-0-dbg"},
          {"reference": "libgdk-pixbuf2.0-0-udeb"},
          {"reference": "libgdk-pixbuf2.0-common"},
          {"reference": "libgdk-pixbuf2.0-dev"},
          {"reference": "libgdk-pixbuf2.0-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "gir1.2-gdkpixbuf-2.0"},
          {"reference": "libgdk-pixbuf2.0-0"},
          {"reference": "libgdk-pixbuf2.0-0-udeb"},
          {"reference": "libgdk-pixbuf2.0-bin"},
          {"reference": "libgdk-pixbuf2.0-common"},
          {"reference": "libgdk-pixbuf2.0-dev"},
          {"reference": "libgdk-pixbuf2.0-doc"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "gir1.2-gdkpixbuf-2.0"},
          {"reference": "libgdk-pixbuf2.0-0"},
          {"reference": "libgdk-pixbuf2.0-0-udeb"},
          {"reference": "libgdk-pixbuf2.0-bin"},
          {"reference": "libgdk-pixbuf2.0-common"},
          {"reference": "libgdk-pixbuf2.0-dev"},
          {"reference": "libgdk-pixbuf2.0-doc"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "gdk-pixbuf2"},
          {"reference": "gdk-pixbuf2-devel"},
          {"reference": "gdk-pixbuf2-modules"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "gdk-pixbuf2"},
          {"reference": "gdk-pixbuf2-devel"},
          {"reference": "gdk-pixbuf2-modules"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-6": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "6",
        "pkgs": [
          {"reference": "gdk-pixbuf2"},
          {"reference": "gdk-pixbuf2-devel"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "gdk-pixbuf2"},
          {"reference": "gdk-pixbuf2-devel"},
          {"reference": "gdk-pixbuf2-tests"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "gdk-pixbuf2"},
          {"reference": "gdk-pixbuf2-devel"},
          {"reference": "gdk-pixbuf2-tests"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "gdk-pixbuf2"},
          {"reference": "gdk-pixbuf2-devel"},
          {"reference": "gdk-pixbuf2-modules"},
          {"reference": "gdk-pixbuf2-xlib"},
          {"reference": "gdk-pixbuf2-xlib-devel"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "gdk-pixbuf2"},
          {"reference": "gdk-pixbuf2-devel"},
          {"reference": "gdk-pixbuf2-modules"},
          {"reference": "gdk-pixbuf2-xlib"},
          {"reference": "gdk-pixbuf2-xlib-devel"}
        ]
      }
    ]
  }
};

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');
}