{"id":"CVE-2026-120749","title":"Dbus: dbus-daemon: dbus-daemon aborts (reply_serial != 0) when a broadcast from the driver cannot be delivered to a monitored bus","summary":"A flaw was found in D-Bus. With a privileged Monitoring client attached (for example dbus-monitor or busctl monitor), an unprivileged local user can cause dbus-daemon to abort if a driver-originated broadcast such as NameOwnerChanged or …","severity":"medium","cvss":6.2,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-617"],"vendor":"Red Hat","product":"dbus","affected":["dbus","dbus","dbus","dbus","dbus","dbus"],"published":"2026-11-06","updated":"2026-11-06","sourceUpdated":"2026-11-06T06:56:57.944Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-120749","references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-120749"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2567978","label":"RHBZ#2567978"},{"url":"https://gitlab.freedesktop.org/dbus/dbus/-/merge_requests/565"},{"url":"https://gitlab.freedesktop.org/dbus/dbus/-/merge_requests/592"},{"url":"https://gitlab.freedesktop.org/dbus/dbus/-/work_items/576"}],"tags":["cve.org"],"ingestedAt":"2026-11-06T07:47:15.877Z","slug":"CVE-2026-120749","body":"## Overview\n\nA flaw was found in D-Bus. With a privileged Monitoring client attached (for example dbus-monitor or busctl monitor), an unprivileged local user can cause dbus-daemon to abort if a driver-originated broadcast such as NameOwnerChanged or ActivatableServicesChanged cannot be delivered to a recipient (for example due to a deny rule or an exceeded outgoing message queue). Driver broadcasts still use serial 0; when delivery fails, composing the monitor error reply asserts reply_serial != 0 and aborts the daemon. This is an incomplete fix for CVE-2023-34969, which only assigned serials for driver messages sent to a single recipient. On the well-known system bus this is a denial of service.\n\n## Affected\n\n- `dbus`\n- `dbus`\n- `dbus`\n- `dbus`\n- `dbus`\n- `dbus`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n### Workarounds\n\nThis can only be done if a monitoring process such as dbus-monitor or busctl monitor is active on the same dbus-daemon instance, which is a privileged operation that can only be done by root or the Unix uid of the message bus. If no monitoring process is active, then the vulnerable code is not reached.","depth":"sunlit","depthScore":34,"depthScoreParts":{"impact":34.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}