Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : PyJWT vulnerabilities (USN-8916-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-8916-1. 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(366020);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/15");
  script_xref(name:"USN", value:"8916-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : PyJWT vulnerabilities (USN-8916-1)");

  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 host has packages installed that
are affected by a vulnerability as referenced in the USN-8916-1 advisory.

    YuSung Han discovered that PyJWT did not properly validate certain JWK keys when performing HMAC
    verification. An attacker could possibly use this issue to forge authentication tokens. This issue only
    affected

    Ubuntu 26.04 LTS. (CVE-2026-102266)

    Rohan Das discovered that PyJWT incorrectly handled redirects when fetching key sets. A remote attacker
    could possibly use this issue to

    cause PyJWT to disclose sensitive information. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04
    LTS, Ubuntu 26.04 LTS. (CVE-2026-102267)

    It was discovered that PyJWT incorrectly recognized certain PEM representations. An attacker who knew the
    public key could possibly use this issue to forge authentication tokens. This issue only affected Ubuntu
    18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 26.04 LTS. (CVE-2026-102268)

    Nuno Lopes discovered that PyJWT incorrectly handled DER public keys when performing HMAC verification. An
    attacker who knew the public key could possibly use this issue to forge authentication tokens.
    (CVE-2026-102271)

    It was discovered that PyJWT did not properly handle certain JWK keys prefixed with a byte-order mark. An
    attacker who knew the public key could possibly use this issue to forge authentication tokens.
    (CVE-2026-102272)

    Charles Vosburgh discovered that PyJWT incorrectly handled certain JWK containers when performing HMAC
    verification. An attacker who knew the public key could possibly use this issue to forge authentication
    tokens. (CVE-2026-102273)

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-8916-1");
  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:"2026/10/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/15");

  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:"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)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04 / 18.04 / 20.04 / 22.04 / 24.04 / 26.04', '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+esm3', 'cves': ['CVE-2026-102266', 'CVE-2026-102271', 'CVE-2026-102272', 'CVE-2026-102273']},
    {'osver': '16.04', 'pkgname': 'python3-jwt', 'pkgver': '1.3.0-1ubuntu0.1+esm3', 'cves': ['CVE-2026-102266', 'CVE-2026-102271', 'CVE-2026-102272', 'CVE-2026-102273']},
    {'osver': '18.04', 'pkgname': 'python-jwt', 'pkgver': '1.5.3+ds1-1ubuntu0.1+esm3', 'cves': ['CVE-2026-102266', 'CVE-2026-102268', 'CVE-2026-102271', 'CVE-2026-102272', 'CVE-2026-102273']},
    {'osver': '18.04', 'pkgname': 'python3-jwt', 'pkgver': '1.5.3+ds1-1ubuntu0.1+esm3', 'cves': ['CVE-2026-102266', 'CVE-2026-102268', 'CVE-2026-102271', 'CVE-2026-102272', 'CVE-2026-102273']},
    {'osver': '20.04', 'pkgname': 'python3-jwt', 'pkgver': '1.7.1-2ubuntu2.1+esm3', 'cves': ['CVE-2026-102266', 'CVE-2026-102268', 'CVE-2026-102271', 'CVE-2026-102272', 'CVE-2026-102273']},
    {'osver': '22.04', 'pkgname': 'python3-jwt', 'pkgver': '2.3.0-1ubuntu0.5', 'cves': ['CVE-2026-102266', 'CVE-2026-102267', 'CVE-2026-102268', 'CVE-2026-102271', 'CVE-2026-102272', 'CVE-2026-102273']},
    {'osver': '24.04', 'pkgname': 'python3-jwt', 'pkgver': '2.7.0-1ubuntu0.3', 'cves': ['CVE-2026-102266', 'CVE-2026-102267', 'CVE-2026-102268', 'CVE-2026-102271', 'CVE-2026-102272', 'CVE-2026-102273']},
    {'osver': '26.04', 'pkgname': 'python3-jwt', 'pkgver': '2.10.1-4ubuntu1.2', 'cves': ['CVE-2026-102266', 'CVE-2026-102267', 'CVE-2026-102268', 'CVE-2026-102271', 'CVE-2026-102272', 'CVE-2026-102273']}
];

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');
}