Linux Distros Unpatched Vulnerability : CVE-2026-66040

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

include('compat.inc');

if (description)
{
  script_id(329727);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/25");

  script_cve_id("CVE-2026-66040");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-66040");

  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.

  - FFmpeg through 8.1.2, fixed in commit b506faf, contains a heap out-of-bounds write vulnerability in the
    native PNG and APNG encoders that allows remote attackers to corrupt heap memory by supplying a crafted
    PNG image with a malicious eXIf chunk. Attackers can craft an eXIf chunk where multiple IFD entries
    reference the same large value payload, causing canonical serialization to expand the output far beyond
    the undersized allocation estimated by add_exif_profile_size(), resulting in png_write_chunk() writing
    tens of thousands of bytes past the buffer boundary, leading to deterministic heap corruption, process
    crash, and potentially arbitrary code execution. (CVE-2026-66040)

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-2026-66040");
  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:P/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:R/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-66040");

  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:"2026/07/24");
  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: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:"p-cpe:/a:debian:debian_linux:ffmpeg");
  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/Debian Linux-14");

  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": "ffmpeg"},
          {"reference": "ffmpeg-doc"},
          {"reference": "libavcodec-dev"},
          {"reference": "libavcodec-extra"},
          {"reference": "libavcodec-extra59"},
          {"reference": "libavcodec59"},
          {"reference": "libavdevice-dev"},
          {"reference": "libavdevice59"},
          {"reference": "libavfilter-dev"},
          {"reference": "libavfilter-extra"},
          {"reference": "libavfilter-extra8"},
          {"reference": "libavfilter8"},
          {"reference": "libavformat-dev"},
          {"reference": "libavformat-extra"},
          {"reference": "libavformat-extra59"},
          {"reference": "libavformat59"},
          {"reference": "libavutil-dev"},
          {"reference": "libavutil57"},
          {"reference": "libpostproc-dev"},
          {"reference": "libpostproc56"},
          {"reference": "libswresample-dev"},
          {"reference": "libswresample4"},
          {"reference": "libswscale-dev"},
          {"reference": "libswscale6"}
        ]
      }
    ]
  },
  "Debian Linux-11": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "11",
        "pkgs": [
          {"reference": "ffmpeg"},
          {"reference": "ffmpeg-doc"},
          {"reference": "libavcodec-dev"},
          {"reference": "libavcodec-extra"},
          {"reference": "libavcodec-extra58"},
          {"reference": "libavcodec58"},
          {"reference": "libavdevice-dev"},
          {"reference": "libavdevice58"},
          {"reference": "libavfilter-dev"},
          {"reference": "libavfilter-extra"},
          {"reference": "libavfilter-extra7"},
          {"reference": "libavfilter7"},
          {"reference": "libavformat-dev"},
          {"reference": "libavformat58"},
          {"reference": "libavresample-dev"},
          {"reference": "libavresample4"},
          {"reference": "libavutil-dev"},
          {"reference": "libavutil56"},
          {"reference": "libpostproc-dev"},
          {"reference": "libpostproc55"},
          {"reference": "libswresample-dev"},
          {"reference": "libswresample3"},
          {"reference": "libswscale-dev"},
          {"reference": "libswscale5"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "ffmpeg"},
          {"reference": "ffmpeg-doc"},
          {"reference": "libavcodec-dev"},
          {"reference": "libavcodec-extra"},
          {"reference": "libavcodec-extra62"},
          {"reference": "libavcodec62"},
          {"reference": "libavdevice-dev"},
          {"reference": "libavdevice62"},
          {"reference": "libavfilter-dev"},
          {"reference": "libavfilter-extra"},
          {"reference": "libavfilter-extra11"},
          {"reference": "libavfilter11"},
          {"reference": "libavformat-dev"},
          {"reference": "libavformat-extra"},
          {"reference": "libavformat-extra62"},
          {"reference": "libavformat62"},
          {"reference": "libavutil-dev"},
          {"reference": "libavutil60"},
          {"reference": "libswresample-dev"},
          {"reference": "libswresample6"},
          {"reference": "libswscale-dev"},
          {"reference": "libswscale9"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "ffmpeg"},
          {"reference": "ffmpeg-doc"},
          {"reference": "libavcodec-dev"},
          {"reference": "libavcodec-extra"},
          {"reference": "libavcodec-extra61"},
          {"reference": "libavcodec61"},
          {"reference": "libavdevice-dev"},
          {"reference": "libavdevice61"},
          {"reference": "libavfilter-dev"},
          {"reference": "libavfilter-extra"},
          {"reference": "libavfilter-extra10"},
          {"reference": "libavfilter10"},
          {"reference": "libavformat-dev"},
          {"reference": "libavformat-extra"},
          {"reference": "libavformat-extra61"},
          {"reference": "libavformat61"},
          {"reference": "libavutil-dev"},
          {"reference": "libavutil59"},
          {"reference": "libpostproc-dev"},
          {"reference": "libpostproc58"},
          {"reference": "libswresample-dev"},
          {"reference": "libswresample5"},
          {"reference": "libswscale-dev"},
          {"reference": "libswscale8"}
        ]
      }
    ]
  }
};

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');
}