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Vulnerability · Published Jul 24, 2026 · Assigned by redhat

CVE-2026-16730Dbus-broker: dbus-broker: session bus denial of service via emfile during peer setup

Medium 5.5

In plain English

A medium-severity security flaw in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.5Medium
Exploit odds (30 days)0.2%top 95.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:10dbus-broker36-5.el10_2ALSA-2026:61340
AlmaLinux:9dbus-broker28-9.el9_8ALSA-2026:61355
Debian:12dbus-brokerno fix listedDEBIAN-CVE-2026-16730
Debian:13dbus-brokerno fix listedDEBIAN-CVE-2026-16730
Debian:14dbus-brokerno fix listedDEBIAN-CVE-2026-16730
Rocky Linux:10dbus-broker0:36-5.el10_2RLSA-2026:61340
Rocky Linux:9dbus-broker0:28-9.el9_8RLSA-2026:61355
Ubuntu:22.04:LTSdbus-brokerno fix listedUBUNTU-CVE-2026-16730
Ubuntu:24.04:LTSdbus-brokerno fix listedUBUNTU-CVE-2026-16730
Ubuntu:26.04:LTSdbus-brokerno fix listedUBUNTU-CVE-2026-16730

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 9 see references
Red Hat Red Hat Update Infrastructure 5 see references
Red Hat Red Hat Update Infrastructure 5 see references
Red Hat Red Hat Update Infrastructure 5 see references
Red Hat Red Hat Update Infrastructure 5 see references
Red Hat Red Hat Update Infrastructure 5 see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat OpenShift Container Platform 4 see references
Red Hat Red Hat OpenShift Container Platform 5 see references

Weakness: CWE-755 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References