Linux Distros Unpatched Vulnerability : CVE-2026-21945

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

include('compat.inc');

if (description)
{
  script_id(297685);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/05/22");

  script_cve_id("CVE-2026-21945");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-21945");

  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.

  - Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of
    Oracle Java SE (component: Security). Supported versions that are affected are Oracle Java SE: 8u471,
    8u471-b50, 8u471-perf, 11.0.29, 17.0.17, 21.0.9, 25.0.1; Oracle GraalVM for JDK: 17.0.17 and 21.0.9;
    Oracle GraalVM Enterprise Edition: 21.3.16. Easily exploitable vulnerability allows unauthenticated
    attacker with network access via multiple protocols to compromise Oracle Java SE, Oracle GraalVM for JDK,
    Oracle GraalVM Enterprise Edition. Successful attacks of this vulnerability can result in unauthorized
    ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Java SE, Oracle GraalVM
    for JDK, Oracle GraalVM Enterprise Edition. Note: This vulnerability applies to Java deployments,
    typically in clients running sandboxed Java Web Start applications or sandboxed Java applets, that load
    and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for
    security. This vulnerability does not apply to Java deployments, typically in servers, that load and run
    only trusted code (e.g., code installed by an administrator). (CVE-2026-21945)

  - A Blind Server-Side Request Forgery (SSRF) vulnerability exists in Oracle Java 21. The vulnerability,
    which leads to Denial of Service (DoS), is present in the x509 certificate path validation mechanism when
    the non-default system property com.sun.security.enableAIAcaIssuers is set to true. (CVE-2026-21945)

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-2026-21945");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-21945");
  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");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-21945");

  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:"2026/01/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/02/03");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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: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:redhat:enterprise_linux:10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openjdk-13");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openjdk-16");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openjdk-18");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openjdk-21");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openjdk-9");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:java-21-ibm-semeru-certified-jdk");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:java-21-ibm-semeru-certified-jdk-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:java-21-ibm-semeru-certified-jdk-headless");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:java-21-ibm-semeru-certified-jdk-jmods");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:java-21-ibm-semeru-certified-jdk-src");
  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/Ubuntu Linux-16.04", "Host/OS/Ubuntu Linux-20.04", "Host/OS/Ubuntu Linux-22.04");

  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")) && empty_or_null(get_one_kb_item("Host/RedHat/rpm-list"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "openjdk-9"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "openjdk-13"},
          {"reference": "openjdk-16"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "openjdk-18"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "java-21-ibm-semeru-certified-jdk"},
          {"reference": "java-21-ibm-semeru-certified-jdk-devel"},
          {"reference": "java-21-ibm-semeru-certified-jdk-headless"},
          {"reference": "java-21-ibm-semeru-certified-jdk-jmods"},
          {"reference": "java-21-ibm-semeru-certified-jdk-src"}
        ]
      }
    ]
  }
};

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 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');
}