Linux Distros Unpatched Vulnerability : CVE-2026-84448

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

include('compat.inc');

if (description)
{
  script_id(348307);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/22");

  script_cve_id("CVE-2026-84448");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-84448");

  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.

  - libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.23.2, the public
    heif_region_item_add_region_inline_mask_data() function in libheif/api/libheif/heif_regions.cc accepts
    mask_data_len without verifying that it equals the byte count required by width and height. A later
    heif_region_get_mask_image() call derives the read length from the region geometry, so an undersized
    stored buffer causes heif_region_get_inline_mask_image() to read beyond the heap allocation and copy
    adjacent bytes into the returned monochrome mask image. This can disclose heap data or crash an
    application that constructs region metadata through the writer API, while the file-parsing path is not
    affected because it validates the canonical mask size. This issue is fixed in version 1.23.2.
    (CVE-2026-84448)

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-2026-84448");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-84448");
  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:S/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:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-84448");

  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:"2026/09/18");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/19");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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: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:libheif");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libheif");
  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/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/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": "heif-gdk-pixbuf"},
          {"reference": "heif-thumbnailer"},
          {"reference": "libheif-dev"},
          {"reference": "libheif-examples"},
          {"reference": "libheif1"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "heif-gdk-pixbuf"},
          {"reference": "heif-thumbnailer"},
          {"reference": "libheif-dev"},
          {"reference": "libheif-examples"},
          {"reference": "libheif-plugin-aomdec"},
          {"reference": "libheif-plugin-aomenc"},
          {"reference": "libheif-plugin-dav1d"},
          {"reference": "libheif-plugin-ffmpegdec"},
          {"reference": "libheif-plugin-j2kdec"},
          {"reference": "libheif-plugin-j2kenc"},
          {"reference": "libheif-plugin-jpegdec"},
          {"reference": "libheif-plugin-jpegenc"},
          {"reference": "libheif-plugin-kvazaar"},
          {"reference": "libheif-plugin-libde265"},
          {"reference": "libheif-plugin-rav1e"},
          {"reference": "libheif-plugin-svtenc"},
          {"reference": "libheif-plugin-x265"},
          {"reference": "libheif-plugins-all"},
          {"reference": "libheif1"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "libheif"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "libheif"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "libheif"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "heif-gdk-pixbuf"},
          {"reference": "heif-thumbnailer"},
          {"reference": "libheif-dev"},
          {"reference": "libheif-examples"},
          {"reference": "libheif-plugin-aomdec"},
          {"reference": "libheif-plugin-aomenc"},
          {"reference": "libheif-plugin-dav1d"},
          {"reference": "libheif-plugin-ffmpegdec"},
          {"reference": "libheif-plugin-j2kdec"},
          {"reference": "libheif-plugin-j2kenc"},
          {"reference": "libheif-plugin-jpegdec"},
          {"reference": "libheif-plugin-jpegenc"},
          {"reference": "libheif-plugin-libde265"},
          {"reference": "libheif-plugin-rav1e"},
          {"reference": "libheif-plugin-svtenc"},
          {"reference": "libheif-plugin-x265"},
          {"reference": "libheif1"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "heif-gdk-pixbuf"},
          {"reference": "heif-thumbnailer"},
          {"reference": "heif-view"},
          {"reference": "libheif-dev"},
          {"reference": "libheif-examples"},
          {"reference": "libheif-plugin-aomdec"},
          {"reference": "libheif-plugin-aomenc"},
          {"reference": "libheif-plugin-dav1d"},
          {"reference": "libheif-plugin-ffmpegdec"},
          {"reference": "libheif-plugin-j2kdec"},
          {"reference": "libheif-plugin-j2kenc"},
          {"reference": "libheif-plugin-jpegdec"},
          {"reference": "libheif-plugin-jpegenc"},
          {"reference": "libheif-plugin-kvazaar"},
          {"reference": "libheif-plugin-libde265"},
          {"reference": "libheif-plugin-rav1e"},
          {"reference": "libheif-plugin-svtenc"},
          {"reference": "libheif-plugin-x265"},
          {"reference": "libheif-plugins-all"},
          {"reference": "libheif1"}
        ]
      }
    ]
  }
};

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');
}