Oracle Linux 10 : nginx (ELSA-2026-6906)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Oracle Linux Security Advisory ELSA-2026-6906.
##

include('compat.inc');

if (description)
{
  script_id(305248);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/07");

  script_cve_id(
    "CVE-2026-27651",
    "CVE-2026-27654",
    "CVE-2026-27784",
    "CVE-2026-32647"
  );
  script_xref(name:"IAVA", value:"2026-A-0280");

  script_name(english:"Oracle Linux 10 : nginx (ELSA-2026-6906)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Oracle Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Oracle Linux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in
the ELSA-2026-6906 advisory.

    - Resolves: RHEL-157874 CVE-2026-32647 nginx: NGINX: Denial of Service or
      Code Execution via specially crafted MP4 files
    - Resolves: RHEL-159433 CVE-2026-27651 nginx: NGINX: Denial of Service via
      undisclosed requests when ngx_mail_auth_http_module is enabled
    - Resolves: RHEL-159525 CVE-2026-27784 nginx: NGINX: Denial of Service due
      to memory corruption via crafted MP4 file

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://linux.oracle.com/errata/ELSA-2026-6906.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:P");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-27654");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-27784");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-27784");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/03/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/04/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/04/07");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-all-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-filesystem");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-mod-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-mod-http-image-filter");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-mod-http-perl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-mod-http-xslt-filter");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-mod-mail");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:nginx-mod-stream");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Oracle Linux Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/OracleLinux", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/local_checks_enabled");

  exit(0);
}


include('rpm2.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_product = get_kb_item('installed_os/local/SSH/0/product');
if (isnull(os_product) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:os_product)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
if (! preg(pattern:"^10([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'Oracle Linux 10.x', 'Oracle Linux ' + os_version);

if (!get_kb_item('Host/RedHat/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Oracle Linux', cpu);

var constraints = [
  {
    'release': '10',
    'pkgs': [
      {'reference':'nginx-1.26.3-2.0.1.el10_1.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-all-modules-1.26.3-2.0.1.el10_1.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-core-1.26.3-2.0.1.el10_1.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-filesystem-1.26.3-2.0.1.el10_1.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-mod-devel-1.26.3-2.0.1.el10_1.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-mod-http-image-filter-1.26.3-2.0.1.el10_1.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-mod-http-perl-1.26.3-2.0.1.el10_1.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-mod-http-xslt-filter-1.26.3-2.0.1.el10_1.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-mod-mail-1.26.3-2.0.1.el10_1.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-mod-stream-1.26.3-2.0.1.el10_1.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-1.26.3-2.0.1.el10_1.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-all-modules-1.26.3-2.0.1.el10_1.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-core-1.26.3-2.0.1.el10_1.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-filesystem-1.26.3-2.0.1.el10_1.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-mod-devel-1.26.3-2.0.1.el10_1.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-mod-http-image-filter-1.26.3-2.0.1.el10_1.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-mod-http-perl-1.26.3-2.0.1.el10_1.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-mod-http-xslt-filter-1.26.3-2.0.1.el10_1.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-mod-mail-1.26.3-2.0.1.el10_1.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'},
      {'reference':'nginx-mod-stream-1.26.3-2.0.1.el10_1.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'2'}
    ]
  }
];

var os_release = get_one_kb_item('installed_os/local/SSH/0/release');
var os_sp = get_one_kb_item('Host/*/minor_release');

var flag = 0;
var reference;
var sp;
var _cpu;
var el_string;
var rpm_spec_vers_cmp;
var epoch;
var allowmaj;
var exists_check;
var cves;
foreach var constraint ( constraints ) {
  # Check that the target release is equal to the affected release
  if (!empty_or_null(constraint['release'])){
    if (constraint['release'] != os_release) continue;
  }
  if (!empty_or_null(constraint['sp'])){
    if (constraint['sp'] != os_sp) continue;
  }
  foreach var pkg ( constraint['pkgs'] ) {
    reference = NULL;
    sp = NULL;
    _cpu = NULL;
    el_string = NULL;
    rpm_spec_vers_cmp = NULL;
    epoch = NULL;
    allowmaj = NULL;
    exists_check = NULL;
    cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        ## (no known rpm to check OR known rpm_exists)
        (!exists_check || rpm_exists(rpm:exists_check)) &&
        rpm_check(sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj, cves:cves)) flag++;
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'nginx / nginx-all-modules / nginx-core / etc');
}