Linux Distros Unpatched Vulnerability : CVE-2026-104635

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

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  script_cve_id("CVE-2026-104635");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-104635");

  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.

  - Uncontrolled Recursion vulnerability in Protobuf.JSON.Decode in elixir-protobuf protobuf allows an
    unauthenticated remote attacker to crash the decoding process via a deeply nested JSON document. Any
    application that decodes attacker-supplied JSON with Protobuf.JSON.decode/3, Protobuf.JSON.decode!/3, or
    Protobuf.JSON.from_decoded/3 into a schema that contains a self-referential or cyclic message type is
    affected. In lib/protobuf/json/decode.ex, the embedded-message clause of decode_singular/3 recurses into
    internal_from_json_data/3 once per nesting level without incrementing or checking the decoder's depth
    counter. The depth guard increase_depth_and_maybe_throw/1 covers only the Google.Protobuf.ListValue and
    Google.Protobuf.Struct clauses, so the recursion_limit option has no effect on user-defined message types.
    Each nesting level allocates a stack frame and heap objects, and a sufficiently deep document exhausts the
    memory of the decoding process. Confidentiality and integrity are not affected. This issue affects
    protobuf: from 0.8.0 before 0.17.1. (CVE-2026-104635)

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-2026-104635");
  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:N/C:N/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:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
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  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-104635");

  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");

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  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/RedHat/rpm-list"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "protobuf"},
          {"reference": "protobuf-compiler"},
          {"reference": "protobuf-devel"},
          {"reference": "protobuf-lite"},
          {"reference": "protobuf-lite-devel"},
          {"reference": "python3-protobuf"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "protobuf"},
          {"reference": "protobuf-compiler"},
          {"reference": "protobuf-devel"},
          {"reference": "protobuf-lite"},
          {"reference": "protobuf-lite-devel"},
          {"reference": "python3-protobuf"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "protobuf"},
          {"reference": "protobuf-compiler"},
          {"reference": "protobuf-devel"},
          {"reference": "protobuf-lite"},
          {"reference": "protobuf-lite-devel"},
          {"reference": "python3-protobuf"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "protobuf"},
          {"reference": "protobuf-compiler"},
          {"reference": "protobuf-devel"},
          {"reference": "protobuf-lite"},
          {"reference": "protobuf-lite-devel"},
          {"reference": "python3-protobuf"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "protobuf"},
          {"reference": "protobuf-compiler"},
          {"reference": "protobuf-devel"},
          {"reference": "protobuf-emacs"},
          {"reference": "protobuf-emacs-el"},
          {"reference": "protobuf-java"},
          {"reference": "protobuf-javadoc"},
          {"reference": "protobuf-lite"},
          {"reference": "protobuf-lite-devel"},
          {"reference": "protobuf-lite-static"},
          {"reference": "protobuf-python"},
          {"reference": "protobuf-static"},
          {"reference": "protobuf-vim"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "protobuf"},
          {"reference": "protobuf-compiler"},
          {"reference": "protobuf-devel"},
          {"reference": "protobuf-emacs"},
          {"reference": "protobuf-emacs-el"},
          {"reference": "protobuf-java"},
          {"reference": "protobuf-javadoc"},
          {"reference": "protobuf-lite"},
          {"reference": "protobuf-lite-devel"},
          {"reference": "protobuf-lite-static"},
          {"reference": "protobuf-python"},
          {"reference": "protobuf-static"},
          {"reference": "protobuf-vim"}
        ]
      }
    ]
  }
};

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');
}