---
id: CVE-2026-16730
title: A flaw was found in dbus-broker
summary: >-
  A flaw was found in dbus-broker. When the process file-descriptor limit is
  reached, EMFILE/ENFILE errors during peer setup (notably SO_PEERPIDFD) are
  handled as fatal failures, causing the broker to exit. A local attacker who
  can open ma…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-755
vendor: Red Hat
product: dbus-broker
affected:
  - dbus-broker (all versions)
  - dbus-broker (all versions)
  - rhui5/cds-kubernetes-rhel9 (all versions)
  - rhui5/cds-rhel9 (all versions)
  - rhui5/haproxy-rhel9 (all versions)
  - rhui5/installer-rhel9 (all versions)
  - rhui5/rhua-rhel9 (all versions)
  - dbus-broker (all versions)
  - openshift/ose-rhel-coreos-9 (all versions)
published: '2026-07-24'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T18:17:56.807'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-16730'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:61340'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:61355'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:66018'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-16730'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2506348'
    label: secalert@redhat.com
  - url: 'https://github.com/bus1/dbus-broker/issues/435'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-16730.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-16730'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-16730'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-07-24T14:47:59.239150Z'
epss: 0.00109
epssPercentile: 0.01112
ingestedAt: '2026-08-22T13:32:35.674Z'
patched:
  - enterprise_linux_baseos_v_10
  - enterprise_linux_baseos_v_9
  - update_infrastructure 5
---

## Overview

A flaw was found in dbus-broker. When the process file-descriptor limit is reached, EMFILE/ENFILE errors during peer setup (notably SO_PEERPIDFD) are handled as fatal failures, causing the broker to exit. A local attacker who can open many connections to the user session bus can trigger this and deny service to the desktop session. Flatpak applications can reach the host session bus through the dbus proxy.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **RHSA-2026:61340** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 10) · released 2026-08-31 · [advisory](https://access.redhat.com/errata/RHSA-2026:61340)
- **RHSA-2026:61355** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 9) · released 2026-08-31 · [advisory](https://access.redhat.com/errata/RHSA-2026:61355)
- **RHSA-2026:66018** · Red Hat · fixed in: Red Hat Update Infrastructure 5 · released 2026-09-09 · [advisory](https://access.redhat.com/errata/RHSA-2026:66018)
- **Red Hat VEX** · Moderate · affected: Red Hat Hardened Images, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat OpenShift Container Platform 4, Red Hat Hardened Images · updated 2026-09-10 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-16730.json)