Dbus: dbus-daemon: dbus-daemon aborts (reply_serial != 0) when a broadcast from the driver cannot be delivered to a monitored bus
Summary
| CVE | CVE-2026-120749 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-11-06 07:17:06 UTC |
| Updated | 2026-11-06 07:17:10 UTC |
| Description | 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 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. |
Risk And Classification
Primary CVSS: v3.1 6.2 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Problem Types: CWE-617 | CWE-617 Reachable Assertion
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 6.2 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 6.2 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Enterprise Linux 10 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Hardened Images | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| gitlab.freedesktop.org/dbus/dbus/-/merge_requests/592 | [email protected] | gitlab.freedesktop.org | |
| gitlab.freedesktop.org/dbus/dbus/-/merge_requests/565 | [email protected] | gitlab.freedesktop.org | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| gitlab.freedesktop.org/dbus/dbus/-/work_items/576 | [email protected] | gitlab.freedesktop.org | |
| access.redhat.com/security/cve/CVE-2026-120749 | [email protected] | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Upstream acknowledges parkma99 as the original reporter. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-10-27T00:00:00.000Z | Reported to Red Hat. |
| CNA | 2026-10-27T00:00:00.000Z | Made public. |
Workarounds
CNA: This 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.
There are currently no legacy QID mappings associated with this CVE.