Bug 2506348 (CVE-2026-16730)

Summary:	CVE-2026-16730 dbus-broker: dbus-broker: session bus denial of service via EMFILE during peer setup
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	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.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2506704, 2506705
Bug Blocks:

Description OSIDB Bzimport 2026-07-23 05:56:13 UTC

A flaw was found in dbus-broker. When the broker's file-descriptor table is exhausted, getsockopt(SO_PEERPIDFD) (and similarly accept-path failures) can return EMFILE/ENFILE. dbus-broker treats these as fatal errors and exits instead of refusing the new connection. A local user or Flatpak application in the same user session can open many dangling session-bus connections to trigger this condition, crashing the session bus and disrupting the desktop session.

Comment 3 errata-xmlrpc 2026-08-31 10:01:47 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:61340 https://access.redhat.com/errata/RHSA-2026:61340

Comment 4 errata-xmlrpc 2026-08-31 10:25:16 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:61355 https://access.redhat.com/errata/RHSA-2026:61355