Linux Distros Unpatched Vulnerability : CVE-2026-19730

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

include('compat.inc');

if (description)
{
  script_id(335233);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/13");

  script_cve_id("CVE-2026-19730");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-19730");

  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.

  - The 'podman quadlet install --replace' command opens the existing destination file with O_CREATE|O_WRONLY
    but omits O_TRUNC. When the initial reflink copy attempt fails (common on non-reflink-capable filesystems
    including many RHEL default XFS configurations), the fallback in ReflinkOrCopy uses io.Copy which performs
    a non-truncating write. If the original Quadlet is larger than the new Quadlet, the file is not truncated
    and content from the original is preserved. The command completes with no warning. There is no risk of
    information leakage as the user already had access to the Quadlet in order to replace it, and in most
    cases, this would only lead to invalid Quadlet files. However, security-related options from the end of
    the old Quadlet could be included in the new Quadlet, and if the truncation resulted in a valid Quadlet
    file, this could result in undesirable behavior. For example, running podman quadlet install --replace to
    remove a single line from the end of a Quadlet - including security-sensitive content, like AddCapability
    - will fail, and the option will continue to be used. Further, with Volume Quadlets, this can include
    additional mounts which can cause content to be unintentionally exposed into containers. If, later, the
    image is updated then compromised content might be leaked to an attacker. The vulnerable code paths are in
    pkg/domain/infra/abi/quadlet.go (lines 338-360, O_CREATE|O_WRONLY without O_TRUNC) and
    vendor/go.podman.io/storage/pkg/fileutils/reflink_linux.go (lines 12-19, non-truncating io.Copy fallback).
    (CVE-2026-19730)

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-2026-19730");
  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:P/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:L/UI:R/S:U/C:L/I:L/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-2026-19730");

  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:"2026/08/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/13");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:9");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:podman");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:podman-catatonit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:podman-docker");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:podman-gvproxy");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:podman-plugins");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:podman-remote");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:podman-tests");
  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/Red Hat Enterprise Linux-10", "Host/OS/Red Hat Enterprise Linux-9");

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

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "podman"},
          {"reference": "podman-docker"},
          {"reference": "podman-remote"},
          {"reference": "podman-tests"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "podman"},
          {"reference": "podman-catatonit"},
          {"reference": "podman-docker"},
          {"reference": "podman-gvproxy"},
          {"reference": "podman-plugins"},
          {"reference": "podman-remote"},
          {"reference": "podman-tests"}
        ]
      }
    ]
  }
};

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');
}