CVE-2026-16730 Dbus-broker: dbus-broker: session bus denial of service via emfile during peer setup
A local attacker can exhaust file descriptors to crash the dbus-broker, denying service to the desktop session.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-16730?
CVE-2026-16730 is a medium-severity denial of service vulnerability in Red Hat Enterprise Linux 10, published on 24 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
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.
Weakness: CWE-755
Which versions are affected by CVE-2026-16730?
Linux distribution packages (10)
dbus-broker AlmaLinux:10 | All versions | 36-5.el10_2 |
dbus-broker AlmaLinux:9 | All versions | 28-9.el9_8 |
dbus-broker Red Hat:enterprise_linux:10.2 | All versions | 0:36-5.el10_2 |
dbus-broker-debuginfo Red Hat:enterprise_linux:10.2 | All versions | 0:36-5.el10_2 |
dbus-broker-debugsource Red Hat:enterprise_linux:10.2 | All versions | 0:36-5.el10_2 |
dbus-broker Red Hat:enterprise_linux:9::baseos | All versions | 0:28-9.el9_8 |
dbus-broker-debuginfo Red Hat:enterprise_linux:9::baseos | All versions | 0:28-9.el9_8 |
dbus-broker-debugsource Red Hat:enterprise_linux:9::baseos | All versions | 0:28-9.el9_8 |
dbus-broker Rocky Linux:10 | All versions | 0:36-5.el10_2 |
dbus-broker Rocky Linux:9 | All versions | 0:28-9.el9_8 |
How do I fix CVE-2026-16730?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-16730 being exploited?
There is no known exploitation of CVE-2026-16730 in the wild and no public exploit code.
Sources
Also known as ALSA-2026:61340, ALSA-2026:61355, CLSA-2026-1788817207, CLSA-2026-1791316945, DEBIAN-CVE-2026-16730, GHSA-77qf-9j4m-ph58 and 5 more.