Linux Distros Unpatched Vulnerability : CVE-2026-70631

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

include('compat.inc');

if (description)
{
  script_id(333325);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/07");

  script_cve_id("CVE-2026-70631");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-70631");

  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 versions from 0.5 up to, but not including, 9.0 contain an uninitialized heap memory disclosure
    vulnerability in the native TIFF decoder in libavcodec/tiff.c. An attacker who can cause FFmpeg to decode
    a crafted TIFF file can supply a valid Deflate-compressed strip that terminates successfully after
    producing fewer bytes than the declared strip requires. The tiff_unpack_zlib() function allocates a heap
    buffer sized for the full declared strip but copies all declared rows via memcpy() regardless of how many
    bytes zlib actually decompressed, causing unwritten bytes that can contain stale data from prior heap
    allocations to be incorporated into decoded image output and potentially exposing sensitive data in
    persistent services. (CVE-2026-70631)

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-2026-70631");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-70631");
  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:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N");
  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:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/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-2026-70631");

  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:"2026/08/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/07");

  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: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:canonical:ubuntu_linux:ffmpeg");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libav");
  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", "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");

  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"}
        ]
      }
    ]
  },
  "Ubuntu Linux-14.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14.04",
        "pkgs": [
          {"reference": "libav"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "ffmpeg"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "ffmpeg"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "ffmpeg"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "ffmpeg"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "ffmpeg"}
        ]
      }
    ]
  },
  "Ubuntu Linux-26.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "26.04",
        "pkgs": [
          {"reference": "ffmpeg"}
        ]
      }
    ]
  }
};

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');
}