Lucene search
+L

RHEL 9 : osbuild-composer (RHSA-2026:61245)

🗓️ 31 Aug 2026 00:00:00Reported by TenableType 
nessus
 nessus
🔗 www.tenable.com👁 2 Views

Authorization bypass and privilege escalation in osbuild-composer via gRPC and x/net dependencies.

Related
Refs
Code
ReporterTitlePublishedViews
Family
osv
OSV
MINI-62CV-58VF-5WV3
18 Jun 202603:09
osv
osv
OSV
MINI-62F5-WWV6-5QCR
7 Jun 202619:24
osv
osv
OSV
MINI-62JV-CCGX-6V32
17 Aug 202601:30
osv
osv
OSV
MINI-62M8-RGPF-8W98
23 Jun 202604:38
osv
osv
OSV
MINI-62V8-5QHC-7626
9 Jun 202611:22
osv
osv
OSV
MINI-6375-8FGF-75WJ
4 Jun 202609:35
osv
osv
OSV
MINI-637Q-948Q-PVQ7
7 Jun 202615:45
osv
osv
OSV
MINI-63FR-96G7-GV7H
7 Jun 202615:45
osv
osv
OSV
MINI-63H7-4M3X-CXXJ
15 Jul 202610:48
osv
osv
OSV
MINI-63PM-Q2M7-97PX
8 Jun 202616:44
osv
Rows per page
#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Red Hat Security Advisory RHSA-2026:61245. The text
# itself is copyright (C) Red Hat, Inc.
##

include('compat.inc');

if (description)
{
  script_id(341627);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/31");

  script_cve_id("CVE-2026-33186", "CVE-2026-39821");
  script_xref(name:"RHSA", value:"2026:61245");

  script_name(english:"RHEL 9 : osbuild-composer (RHSA-2026:61245)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat host is missing one or more security updates for osbuild-composer.");
  script_set_attribute(attribute:"description", value:
"The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as
referenced in the RHSA-2026:61245 advisory.

    A service for building customized OS artifacts, such as VM images and OSTree commits, that uses osbuild
    under the hood. Besides building images for local usage, it can also upload images directly to cloud.  It
    is compatible with composer-cli and cockpit-composer clients.

    Security Fix(es):

    * google.golang.org/grpc/grpc-go: google.golang.org/grpc/authz: gRPC-Go: Authorization bypass due to
    improper HTTP/2 path validation (CVE-2026-33186)

    * golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect
    Punycode label processing (CVE-2026-39821)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and
    other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise 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://access.redhat.com/security/updates/classification/#important");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2449833");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2480756");
  # https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_61245.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?438aafb5");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:61245");
  script_set_attribute(attribute:"solution", value:
"Update the RHEL osbuild-composer package based on the guidance in RHSA-2026:61245.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-39821");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-33186");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_cwe_id(551, 1289);
  script_set_attribute(attribute:"vendor_severity", value:"Important");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/03/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/31");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:rhel_e4s:9.2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:osbuild-composer");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:osbuild-composer-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:osbuild-composer-dnf-json");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:osbuild-composer-worker");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Red Hat 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", "redhat_repos.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/cpu");

  exit(0);
}


include('rpm2.inc');
include('rhel.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) || 'Red Hat' >!< os_product) audit(AUDIT_OS_NOT, 'Red Hat');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'Red Hat');
if (!rhel_check_release(operator: 'eq', os_version: os_version, rhel_version: '9.2')) audit(AUDIT_OS_NOT, 'Red Hat 9.2', 'Red Hat ' + 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$" && 's390' >!< cpu && 'aarch64' >!< cpu && 'ppc' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Red Hat', cpu);

var constraints = [
  {
    'release': '9',
    'sp': '2',
    'repo_relative_urls': [
      'content/aus/rhel9/9.2/x86_64/appstream/debug',
      'content/aus/rhel9/9.2/x86_64/appstream/os',
      'content/aus/rhel9/9.2/x86_64/appstream/source/SRPMS',
      'content/e4s/rhel9/9.2/aarch64/appstream/debug',
      'content/e4s/rhel9/9.2/aarch64/appstream/os',
      'content/e4s/rhel9/9.2/aarch64/appstream/source/SRPMS',
      'content/e4s/rhel9/9.2/ppc64le/appstream/debug',
      'content/e4s/rhel9/9.2/ppc64le/appstream/os',
      'content/e4s/rhel9/9.2/ppc64le/appstream/source/SRPMS',
      'content/e4s/rhel9/9.2/s390x/appstream/debug',
      'content/e4s/rhel9/9.2/s390x/appstream/os',
      'content/e4s/rhel9/9.2/s390x/appstream/source/SRPMS',
      'content/e4s/rhel9/9.2/x86_64/appstream/debug',
      'content/e4s/rhel9/9.2/x86_64/appstream/os',
      'content/e4s/rhel9/9.2/x86_64/appstream/source/SRPMS',
      'content/e6s/rhel9/9.2/aarch64/appstream/debug',
      'content/e6s/rhel9/9.2/aarch64/appstream/os',
      'content/e6s/rhel9/9.2/aarch64/appstream/source/SRPMS',
      'content/e6s/rhel9/9.2/ppc64le/appstream/debug',
      'content/e6s/rhel9/9.2/ppc64le/appstream/os',
      'content/e6s/rhel9/9.2/ppc64le/appstream/source/SRPMS',
      'content/e6s/rhel9/9.2/s390x/appstream/debug',
      'content/e6s/rhel9/9.2/s390x/appstream/os',
      'content/e6s/rhel9/9.2/s390x/appstream/source/SRPMS',
      'content/e6s/rhel9/9.2/x86_64/appstream/debug',
      'content/e6s/rhel9/9.2/x86_64/appstream/os',
      'content/e6s/rhel9/9.2/x86_64/appstream/source/SRPMS'
    ],
    'pkgs': [
      {'reference':'osbuild-composer-76.1-7.el9_2', 'sp':'2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'osbuild-composer-core-76.1-7.el9_2', 'sp':'2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'osbuild-composer-dnf-json-76.1-7.el9_2', 'sp':'2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'osbuild-composer-worker-76.1-7.el9_2', 'sp':'2', 'rpm_spec_vers_cmp':TRUE}
    ]
  }
];

var applicable_repo_urls = rhel_determine_applicable_repository_urls(constraints:constraints);
if(applicable_repo_urls == RHEL_REPOS_NO_OVERLAP_MESSAGE) exit(0, RHEL_REPO_NOT_ENABLED);

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 repo_relative_urls;
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;
  }

  if (!empty_or_null(constraint['repo_relative_urls'])) repo_relative_urls = constraint['repo_relative_urls'];

  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 &&
        rhel_decide_repo_relative_url_check(required_repo_url_list:repo_relative_urls) &&
        (applicable_repo_urls || (!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)
{
  var subscription_caveat = '\n' +
    'NOTE: This vulnerability check contains fixes that apply to\n' +
    'packages only available in the Red Hat Enterprise Linux\n' +
    'Update Services for SAP Solutions repository.\n' +
    'Access to this repository requires a paid RHEL subscription.\n';
  var extra = NULL;
  if (isnull(applicable_repo_urls) || !applicable_repo_urls) extra = subscription_caveat + rpm_report_get() + redhat_report_repo_caveat();
  else extra = subscription_caveat + rpm_report_get();
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : extra
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'osbuild-composer / osbuild-composer-core / etc');
}

Data

Build on a solid foundation with Vulners data

We provide the essential building blocks for cybersecurity solutions with comprehensive, structured, and constantly updated vulnerability and exploits data

Api

Power your application with Vulners API

The Vulners REST API offers reliable, high-performance access to vulnerability intelligence, with 99.9% SLA uptime and CDN-backed data delivery for seamless global access

App

Assess and manage vulnerabilities with Vulners tools

Built on top of Vulners' database and SDK, end-user solutions give security professionals and developers lightweight and powerful tools for vulnerability remediation