Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS / 26.10 : PyJWT vulnerabilities (USN-8934-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-8934-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('compat.inc');

if (description)
{
  script_id(369329);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/21");
  script_xref(name:"USN", value:"8934-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS / 26.10 : PyJWT vulnerabilities (USN-8934-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS / 26.10 host has packages
installed that are affected by a vulnerability as referenced in the USN-8934-1 advisory.

    Kingsley Olukanni discovered that PyJWT did not properly handle unknown key identifiers when retrieving
    signing keys. An attacker could possibly use this issue to amplify requests to the configured key
    endpoint, resulting in a denial of service. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS,
    Ubuntu 26.04 LTS and Ubuntu 26.10. (CVE-2026-101917)

    Ekalabya Ghosh discovered that PyJWT did not properly handle certain recursively nested JSON payloads. An
    attacker could possibly use this issue to cause an application to fail, resulting in a denial of service.
    (CVE-2026-101918)

    Pedram Hayati discovered that PyJWT did not properly handle malformed RSA keys in a JSON Web Key Set. An
    attacker could possibly use this issue to cause authentication failures or a denial of service. This issue
    only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS,

    Ubuntu 26.04 LTS and Ubuntu 26.10. (CVE-2026-102274)

    It was discovered that PyJWT did not properly validate certain OKP private key components. An attacker
    could possibly use this issue to confuse the identity of public and private keys, and use a stolen sender-
    constrained token without the legitimate private key. This issue only affected Ubuntu 22.04 LTS, Ubuntu
    24.04 LTS, Ubuntu 26.04 LTS and Ubuntu 26.10. (CVE-2026-102275)

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

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/notices/USN-8934-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected python-jwt and / or python3-jwt packages.");
  script_set_attribute(attribute:"risk_factor", value:"Medium");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/10/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/21");

  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: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:canonical:ubuntu_linux:26.10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python-jwt");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3-jwt");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"Ubuntu Security Notice (C) 2026 Canonical, Inc. / NASL script (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");

  exit(0);
}

include('debian_package.inc');

if ( ! get_kb_item('Host/local_checks_enabled') ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('16.04' >< os_release || '18.04' >< os_release || '20.04' >< os_release || '22.04' >< os_release || '24.04' >< os_release || '26.04' >< os_release || '26.10' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04 / 18.04 / 20.04 / 22.04 / 24.04 / 26.04 / 26.10', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) 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$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Ubuntu', cpu);

var pkgs = [
    {'osver': '16.04', 'pkgname': 'python-jwt', 'pkgver': '1.3.0-1ubuntu0.1+esm4', 'cves': ['CVE-2026-101918', 'CVE-2026-102274']},
    {'osver': '16.04', 'pkgname': 'python3-jwt', 'pkgver': '1.3.0-1ubuntu0.1+esm4', 'cves': ['CVE-2026-101918', 'CVE-2026-102274']},
    {'osver': '18.04', 'pkgname': 'python-jwt', 'pkgver': '1.5.3+ds1-1ubuntu0.1+esm4', 'cves': ['CVE-2026-101918', 'CVE-2026-102274']},
    {'osver': '18.04', 'pkgname': 'python3-jwt', 'pkgver': '1.5.3+ds1-1ubuntu0.1+esm4', 'cves': ['CVE-2026-101918', 'CVE-2026-102274']},
    {'osver': '20.04', 'pkgname': 'python3-jwt', 'pkgver': '1.7.1-2ubuntu2.1+esm4', 'cves': ['CVE-2026-101918', 'CVE-2026-102274']},
    {'osver': '22.04', 'pkgname': 'python3-jwt', 'pkgver': '2.3.0-1ubuntu0.6', 'cves': ['CVE-2026-101917', 'CVE-2026-101918', 'CVE-2026-102274', 'CVE-2026-102275']},
    {'osver': '24.04', 'pkgname': 'python3-jwt', 'pkgver': '2.7.0-1ubuntu0.4', 'cves': ['CVE-2026-101917', 'CVE-2026-101918', 'CVE-2026-102274', 'CVE-2026-102275']},
    {'osver': '26.04', 'pkgname': 'python3-jwt', 'pkgver': '2.10.1-4ubuntu1.3', 'cves': ['CVE-2026-101917', 'CVE-2026-101918', 'CVE-2026-102274', 'CVE-2026-102275']},
    {'osver': '26.10', 'pkgname': 'python3-jwt', 'pkgver': '2.13.0-1ubuntu1.1', 'cves': ['CVE-2026-101917', 'CVE-2026-101918', 'CVE-2026-102274', 'CVE-2026-102275']}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var osver = NULL;
  var pkgname = NULL;
  var pkgver = NULL;
  if (!empty_or_null(package_array['osver'])) osver = package_array['osver'];
  if (!empty_or_null(package_array['pkgname'])) pkgname = package_array['pkgname'];
  if (!empty_or_null(package_array['pkgver'])) pkgver = package_array['pkgver'];
  if (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  if (osver && pkgname && pkgver) {
    if (deb_check(release:osver, prefix:pkgname, reference:pkgver, cves:cves)) flag++;
  }
}

if (flag)
{
  var extra = '';
  extra += ubuntu_report_get();
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : extra
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'python-jwt / python3-jwt');
}