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No exploitation reportedFix availableAwaiting NVD analysis

CVE-2026-16730

Dbus-broker: dbus-broker: session bus denial of service via emfile during peer setup

No exploitation reported by the sources we read.

  • Published2026-07-24
  • WeaknessCWE-755

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC
  1. 2026-07-2411:26CVE publishedCNA

Versions per branch

Products declared by the CNA10 products

As redhat, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

4 more products in the CVE record.

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-11-05

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • dbus-brokerUbuntu:26.04:LTSall versions · no fixed version listed
  • dbus-brokerUbuntu:24.04:LTSall versions · no fixed version listed
  • dbus-brokerUbuntu:22.04:LTSall versions · no fixed version listed
  • dbus-brokerTuxCare:AlmaLinux:9.6all versions · fixed in 28-7.el9_6.tuxcare.els1
  • dbus-brokerTuxCare:AlmaLinux:9.2all versions · fixed in 28-7.el9.tuxcare.els1
  • dbus-brokerRocky Linux:10all versions · fixed in 0:36-5.el10_2
  • dbus-brokerRocky Linux:9all versions · fixed in 0:28-9.el9_8
  • dbus-brokerRed Hat:enterprise_linux:10.2all versions · fixed in 0:36-5.el10_2and 2 other packages

6 more package ranges on OSV.dev

Vendor advisories

  • CVE-2026-16730 Red Hat Product Security31 products fixed · 2 known affected

    dbus-broker: dbus-broker: session bus denial of service via EMFILE during peer setup

    dbus-broker.src as a component of Red Hat Hardened Images · openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4

  • RHSA-2026:66018 Red Hat Product Security5 products fixed

    Red Hat Security Advisory: Red Hat Update Infrastructure 5.3 security update

  • RHSA-2026:61355 Red Hat Product Security13 products fixed

    Red Hat Security Advisory: dbus-broker security update

  • RHSA-2026:61340 Red Hat Product Security13 products fixed

    Red Hat Security Advisory: dbus-broker security update

Full record on NVD

Fix

  1. Vendor fix Red Hat Product Security RHSA-2026:66018 · 5 productsThe container images provided by this release, apart from the installer, should be deployed using rhui-installer utility. See the official documentation for more details.
  2. Vendor fix Red Hat Product Security RHSA-2026:61355 · 13 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  3. Workaround from the vendor Red Hat Product Security RHSA-2026:66018 · 5 productsMitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
  4. No fix available, says the vendor Red Hat Product Security CVE-2026-16730 · 1 productFix deferred
  5. No fix available, says the vendor Red Hat Product Security CVE-2026-16730 · 1 productAffected

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Published
2026-07-24
Last Modified
2026-11-05
NVD status
Awaiting Analysis
GitHub Advisory
GHSA-77qf-9j4m-ph58

Frequently asked questions

What is CVE-2026-16730?

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.

Is CVE-2026-16730 actively exploited?

Active exploitation of CVE-2026-16730 has not been confirmed. Its EPSS score was 0.2% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-16730?

CVE-2026-16730 has a CVSS v3 base score of 5.5 (MEDIUM severity), with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

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